ab-A prefix meaning from, away from, or outside of.
abaxialThe surface of an organ facing away from the axis; e.g. the lower surface of a lateral organ such as a
leaf or
petal.
abortTo abandon development of a structure or organ.
abscissionshedding of an organ that is mature or aged, e.g. a ripe
fruit or an old leaf.
abscission zonea specialised layer of tissue formed, for example, at the base of a
petiole or
pedicel that allows the organ to be shed by abscission when it is ripe or senescent.
acaulescentAn adjective descriptive of a plant that has no apparent
stem, or at least none visible above ground. Examples include some species of
Agave,
Oxalis and
Attalea.
accrescentIncreasing in size with age, such as a calyx that continues to grow after the corolla has fallen, for example in
Physalis peruviana.
-aceaeThe suffix added to the stem of a generic name to
form the name of a
family.
acheneA dry 1-seeded indehiscent fruit; e.g. in the genus
Ranunculus.
acicularSlender or needle-shaped.
acropetalMoving from roots to leaves, e.g. of molecular signals in plants.
acrophyllThe regular leaves of a mature plant, produced above the base; usually in contrast to bathyphyll.
acrostichoid(describing a
type of sorus) covering the entire abaxial surface of the
frond, usually densely so, as in
Elaphoglossum and
Acrostichum.
actino-A prefix that indicates a radial form.
actinodromous(leaf venation) palmate or radially arranged venation with three or more primary
veins arising from at or near the base of the leaf, the primary veins reaching the margin or not.
actinomorphicregular; radially symmetrical; may be bisected into similar halves in at least two planes. Applies e.g. to steles and flowers in which the perianth segments within each
whorl are alike in size and shape; compare regular; contrast with asymmetrical, irregular, zygomorphic.
aculeateArmed with prickles; e.g. the stem of a rose.
acuminateTapering gradually to a point.
acuteSharply pointed; converging edges making an angle of less than 90°; compare obtuse.
ad-A prefix meaning near or towards. Also meaning added to.
adaxialThe surface of an organ facing towards the axis; e.g. the upper surface of a lateral organ such as a leaf or petal.
adnategrown or fused to an organ of a different kind, especially along a margin; e.g. a stamen fused to a petal; cf. connate.
adventitiousA structure produced in an abnormal position; e.g. an adventitious bud produced from a stem rather than from the axil of a leaf.
adventiveIntroduced accidentally (usually referring to weeds).
aerialOf the air; growing or borne above the surface of the ground.
aestivationThe arrangement of sepals and petals or their lobes in an unexpanded flower bud; cf.
vernation, the arrangement of leaves in a bud.
aff. (affinis)With affinity to others, akin to; often used for a provisionally recognized but unnamed
taxon considered close to that name, perhaps a hybrid or extreme variant.
aggregate fruitA cluster of fruits formed from the free carpels of one flower, e.g.
blackberry; cf.
multiple fruit.
agricultural weedsee weed.
alatehaving a wing or wings.
albumenan older name for the
endosperm of
flowering plants. Except for being a
storage tissue for nutrients, it is not at all like the albumen (
egg white) of animals.
albuminous(seeds) containing endosperm.
-alesSuffix to the stem of a generic name or descriptive name to indicate that it applies to a taxon of the rank of
order.
aliena plant introduced to an area outside its natural range (foreign, exotic, non-native, non-indigenous).
alkaloidMolecule with a nitrogenous base, many used as drugs; e.g.
morphine,
quinine,
strychnine.
alternate(as adjective) leaves or flowers borne singly at different levels along a stem includes spiralled parts; or (as preposition) when something occurs between something else, for example stamens alternating with petals; compare opposite.
amentSynonym of
catkin.
amphitropousWhen the
ovule is bent so that both ends are near each other; cf. anatropous, campylotropous, orthotropous.
amplexicaulWith the base dilated and clasping the stem, usually of leaves.
anastomosingWhen veins are joined by cross-veins to form a network.
anatropousWhen an ovule is inverted so that the micropyle faces the
placenta (this is the most common ovule orientation in flowering plants); cf. amphitropous, campylotropous, orthotropous.
androdioeciousOf plants, having bisexual flowers and male flowers on separate individuals; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
andromonoeciousof a species, with bisexual flowers and male flowers on the same plant; cf. gynomonoecious
androeciumMale parts of flower; the stamens of a flower collectively; cf.
gynoecium. Abbreviation: A. For instance A 3+3 indicates 6 stamens in two whorls.
androgynophoreA stalk bearing both the androecium and gynoecium of a flower above the level of insertion of the perianth.
androgynousWith male and female flowers in the same
inflorescence.
andromonoecioushaving bisexual and male flowers on the same individual; cf. andromonoecious, polygamodioecious, polygamomonoecious, polygamous.
anemophilyPollination by
wind.
angiospermsflowering plants; plants with developing seeds enclosed in an ovary.
anisomerythe condition of having a floral whorl with a different (usually smaller) number of parts from the other floral whorls.
anisotomicbranching with branches having unequal diameters, such as a
trunk and its branch, compare to isotomic.
annualA plant that completes its life cycle and dies within one year.
anastomosebranching then rejoining.
anteriorpositioned in front of, towards the apex, distal.
antherPollen-bearing part of the stamen.
anthesis1. (of a flower) the period during which
pollen is presented and/or the
stigma is receptive.2. (of a
flowering plant) the period during which flowers in anthesis are present. note: not defined for some cases, such as when
pollen is released in the bud.
anticlinalPointing up away from or perpendicular to a surface, cf. periclinal.
antrorseDirected towards or upwards, e.g. of hairs on a stem; cf. retrorse.
apetalousWithout petals.
apex(plural apices) The tip; the point furthest from the point of attachment.
aphananthousinconspicuous (unshowy) in relation to flowers, as opposed to phaneranthous (showy).
aphlebia(plural aphlebiae) Imperfect or irregular leaf endings commonly found on
ferns and fossils of ferns from the Carboniferous Period.
apiculate(Usually referring to a leaf) terminating in a short sharp flexible point; less abrupt than mucronate.
apiphilyA form of
pollination whereby pollen is distributed by honey bees.
apo-A prefix meaning away from, separate, without.
apocarpousOf a gynoecium consisting with one or more carpels which are free from one another (or almost so); e.g.
Ranunculaceae,
Dilleniaceae.
apomixisReproduction, where viable
seed or
spores are produced without fertilization. A plant produced in this way is an apomict.
apomorphy(in
cladistics) a "different form" from the form of an ancestor, i.e., an innovation, of use in determining membership in a clade.
apophysisthe external part of a
cone scale; an outgrowth of an organ or enlargement of a stem.
appendageA secondary part attached to the main structure; an external growth that seldom has any obvious function, hence appendiculate.
appendiculateHaving the nature of, or bearing appendage(s).
appressedPressed closely, but not fused; e.g. leaves against a stem.
aquaticPlants whose natural
habitat is
water: living in or on water for all or a substantial part of the
organism's life span, generally restricted to fresh or inland waters.
arachnoidCobwebby, from being covered with fine white hairs.
arborescentTree-like in growth or general appearance.
arboretum(plural arboreta) A taxonomically arranged collection of trees.
archaeophyteAn non-native plant that has been present in a geographic area for some time; cf.
neophyte.
areolateHaving areoles, being composed of areoles, as an areolate crustose
lichen.
areole(from areola) A space between the threads of a net; e.g. that part of a leaf surface defined by each of the elements of a vein network; as with cacti, the area between the veinlets of a leaf or the region of a
cactus bearing the flowers and/or spines. In lichenology, an areole is a polygonal piece of a
thallus surface when a crustose lichen it broken up like old dried and cracked paint, or like the polygonal "islands" of dried mud in a dry lake bed.
aril(adjective arillate): A membranous or fleshy appendage (formed by expansion of the funicle) which partly or wholly covers a seed; e.g. the fleshy outer layer of
lychee fruit and as found in
Sapindaceae.
aristateWith a stiff,
bristle-like
awn or tip.
articleA segment of a jointed stem or of a fruit with constrictions between the seeds; an organ part that separates easily from the rest of the organ at a joint or articulation.
articulateJointed; separating freely, leaving a clean scar; for example the fronds of certain ferns where they join the
rhizome.
ascendingSpreading horizontally, then becoming erect.
ascocarpThe fruiting body (sporocarp) of an ascomycete
fungus.
ascomyceteA member of the Ascomycota.
AscomycotaA division (biology) or
phylum of fungi commonly called sac fungi. It is separated from the division Basidiomycota
asexual reproductionreproduction that does not involve gametes; i.e.
vegetative reproduction.
asymmetricalirregular, unequal, lacking any plane of symmetry.
attenuateNarrowing gradually.
auricle(adjective auriculate): Ear-shaped
lobe.
awnLong, bristle-like appendage; e.g. terminating or on the back of glumes and/or lemmas of some grass spikelets.
axilThe upper angle between one part of a plant and another; e.g. the stem and a leaf.
axileOn an axis; of a placenta, on the central axis of the ovary.
axillaryBorne in or arising from the axil of a leaf.
axisthe main stem of a whole plant or
inflorescence.
baculiformrod-like, longer than wide, c.f. cylindrical
barba rear-facing point, as in a
fish hook.
barbedwith (barbs pointing in one direction.)
barbellatewith barbed hairs (barbellae)
barkthe protective external layer of tissue on the stems and roots of trees and shrubs; includes all of the living and non-living tissue external to the
cambium.
basalat the base, situated or attached at the base.
basifixedsomething attached by its base; e.g. an anther attached to the filament. compare: dorsifixed
basipetaldeveloping sequentially from the apex towards the base (i.e. with the youngest towards the base); e.g. of flowers in an inflorescence. Also, moving from leaves to roots, e.g. of molecular signals in plants.
bathyphylla specialized leaf that is produced at the base of a plant, usually when the plant is immature, and which serves to anchor the plant to a substrate; especially notable in the
fern Teratophyllum. (compare: acrophyll).
beaka prominent pointed terminal projection, especially of a carpel or fruit. adj. beaked
berryan indehiscent fruit, with the seeds immersed in the pulp, for instance
tomato.
bi-prefix meaning two, for example bisulcate, two sulci or grooves. For other uses, see specific -suffix
biennialplant which completes its life cycle and dies within the second year; usually also forms a basal
rosette of leaves the first year and flowers and fruits the second year.
bifidforked; cut in two for about half its length. See also trifid.
bifoliatehaving 2 leaflets (a type of compound leaf).
bifusiformfusiform with a pinch in the middle
bilabiatehaving two lips; e.g. the form of the petals in many irregular flowers.
bilateralarranged on opposite sides; e.g. leaves on a stem.
biloculatehaving two loculi; e.g. in the anthers.
binomialmaking use of names consisting of two words to form the scientific name (or combination) in a Latin form. For example, where the first is the name of the genus to which the species belongs, and the second is the
epithet given to that species to distinguish it from others in the same genus.
binomial nomenclaturethe system of
nomenclature in which the scientific name of a species (and not of a taxon at any other rank) is a combination of two names, the first name being the generic name. The second name is referred to botanically as the specific epithet. Note that the two names constitute the species name, not just the second word.
bipinnatetwice pinnate; for example of a compound leaf with individual leaflets pinnately divided.
bipinnatisecta pinnatisect leaf with deeply dissected segments.
bisexualbearing both male and female reproductive organs; usually, flowers with both stamens and carpels;
synonymous with
hermaphrodite, synoecious, monoclinous. Bisexual flowers only occur on monoecious plants. See also androgynous, monoicous, and Plant reproductive morphology.
bitegmic(of an ovule), covered by two integuments.
biternateternate, with each division divided into three
bivalvehaving two
valves or hinged parts. See also trivalve.
bladethe lamina or flattened part of a leaf, excluding the stalk.
blooma fine white or bluish waxy powder occurring on plant parts, usually stems, leaves and fruits. It is easily removed by rubbing.
bolethe trunk of a
tree, usually below the lowest branch; cf.
canopy.
bractmodified leaf associated with flower or inflorescence, differing in shape, size or colour from other leaves (and without an axillary bud).
bracteatepossessing bracts.
bracteolesmall bracts borne singly or in pairs on the
pedicel or calyx.
bracteolatepossessing bracteoles (bractlets)
bractletbracteole
branchleta small branch.
brevideciduousa plant that loses all of its leaves briefly, so that it is leafless for, e.g., about two weeks.
bristle(adjective: bristly) straight stiff hair (smooth or with minute teeth) or upper part of an awn (when the latter is bent and has a lower, stouter, and usually twisted part, called the
column).
brochidodromouspinnate leaf venation in which the secondary veins do not terminate at the leaf margin, but are joined in a succession of prominent arcs.
bryophyteinformally, a collective term for mosses, hornworts and liverworts. Formally, these plants are placed in three separate divisions: hornworts (Anthocerophyta), liverworts (
Marchantiophyta) and mosses (Bryophyta).
bulb(adj. bulbiferous), thick storage organ, usually underground, consisting of a stem and leaf bases (the inner ones fleshy).
bulbela bulb arising from another bulb.
bulbilsmall
deciduous bulb or
tuber formed in the axil of a leaf or pinna; a means of vegetative propagation.
bulbleta bulb arising from another bulb; a bulbil.
bullatesurface with rounded or globular blisters.
burrloosely, a prickly fruit; a rough or prickly
propagule consisting of a seed or fruit and associated floral parts or bracts.
buttress roota
root growing from the above-ground stem or trunk, and providing support, as in the case of
Ficus macrophylla, the Moreton Bay fig.
byssoida growth form of a lichen thallus that is whispy, like teased
wool.
C, C−, C+In lichenology, "C" is an abbreviation for the test result of placing 5% solution of calcium hypochlorite or sodium hypochlorite (e.g., household bleach without additives) on the
cortex or the medulla of a lichen, to note the change in color, with no reaction noted as "C−", and production of a bright colour noted as "C+".
caducousfalling off early, for example the sepals of poppies, that fall off when the petals begin to open; compare persistent and fugacious.
caespitosetufted; e.g. the growth form of some grasses.
calcareousA
soil type that is rich in
calcium carbonate. A lichen substrate rock type that is largely composed of calcium carbonate.
callosecallous, hardened, thickened.
callus1. (plural: calli), a protruding mass of tissue.2. undifferentiated tissue growth formed in response to wounding; may be grown
in vitro.3. in orchids, fleshy outgrowths from the
labellum which can be variously shaped from papillae to plates4. in grasses, a hardened extension from the base of a floret (formed from the rachilla joint and/or the base of the lemma) which may or may not elongate and is often covered in hairs or bristles.
calyciflorous"calyx flowered", with petals and stamens attached to the calyx
calycophylla leaf-like structure formed from a
sepal or calyx lobe which enlarges, usually many-fold, before or after anthesis, especially when most of the sepals or calyx lobes retain their original size. More extreme than an accrescent calyx, calycophylls are found in
Rubiaceae. cf. semaphyll, pterophyll.
calyculatehaving an epicalyx.
calyculus(1) a cup-shaped structure formed from bracts, (2) in some
Asteraceae, a circle of bracts below the involucre.
calyptraa hood or lid; see
operculum.
calyx(plural calyces) the outer whorl of a flower, usually green; the sepals of one flower collectively.
calyx tubea tube formed by the fusion of the sepals (calyx), at least at the base.
campanulatebell-shaped.
camptodromouspinnate venation in which the secondary veins curve toward the margins, in some cases becoming nearly parallel with them, and not reconnecting with other veins to form loops.
campylotropouswhen the ovule is oriented transversely (i.e. with its axis at right angles to its stalk) and with a curved embyro sac; cf. amphitropous, anatropous, orthotropous.
canaliculatechannelled; with a longitudinal groove.
canescentapproaching white in color, as in a leaf covered with white down or wool.
canopythe branches and foliage of a tree; crown; cf. trunk. Also refers to the protective upper layer of a
forest.
capillary1. (noun) a tube, pore or passage with a narrow internal
cross-section.2. (adjective) slender, hair-like.
capitatewith knob-like head; of an inflorescence, with the flowers unstalked and aggregated into a dense cluster; of a stigma, like the head of a pin.
capituluma dense cluster of sessile, or almost sessile, flowers or florets; e.g. a flower head in the daisy
family Asteraceae. see
pseudanthium and pseudanthium.
capsulea dry fruit formed from two of more united carpels and dehiscing when ripe (usually by splitting into pieces or opening at summit by teeth or pores).
carina(adjective carinate) see keel.
carinal canala longitudinal cavity in the stems of
Equisetum and extinct Equisetopsida, coinciding with a ridge in the stem surface.
carpelthe basic female reproductive organ in angiosperms, either consisting of a single
sporophyll or a single
locule of a compound ovary, with a style and a stigma. The gynoecium is the collective term for all of the carpels of a single flower.
cartilaginoushard and tough; gristly.
caryopsisa dry, indehiscent, one-seeded fruit in which the seed coat is closely fused to the fruit wall, as in most grasses.
Casparian stripa continuous band of
suberin in the radial primary
cell walls of the
endodermis in
vascular plant stems and roots that forms a permeability barrier to the passive diffusion of external water and solutes into the
vascular tissue.
casual aliena plant that appears with no apparent human assistance but does not develop a sustained
population(s). Plants that persist only by new introductions; cf. alien.
cataphyllEarly leaf forms of plants or shoots, such as cotyledons, bud-scales, rhizome-scales; anatomically they are leaves, but do not develop to perform the usual functions of photosynthetic leaves.
catkina spike, usually pendulous, in which the mostly small flowers are unisexual and without a conspicuous perianth; e.g. willows, poplars, oaks and
casuarinas. The individual flowers often have scaly bracts; they are generally
wind-pollinated. The catkins are usually shed as a unit.
caudatehaving a narrow tail-like appendage or tip, e.g. a drip tip, cf. acuminate
caudex (plural: caudices)Literally the stem of a plant, but also used to mean a
rootstock, or particularly a basal stem structure or storage organ from which new growth arises. See also caudiciform
caudiciformLiterally meaning "stem-like" or "caudex-like", is sometimes used to mean "
pachycaul", meaning "thick-stemmed".
caulineborne on an aerial stem, e.g. leaves, flower or fruits (when applied to the latter two organs, usually referring to older stems; = cauliflorous).
cell1. basic (microscopic) unit of plant structure, generally consisting of compartments in a viscous fluid surrounded by a wall.2. cavity of an anther or ovary.
centrifixedof a two-branched organ attached by its centre, e.g. a hair, or anther.
cespitosealternative spelling of caespitose.
chartaceouswith a papery texture.
chambercavity of an ovary.
channelledsunken below the surface, resulting in a rounded channel.
chasmogamousof flowers that are pollinated when the perianth is open; cf. cleistogamous.
chasmophytea plant adapted to growing in crevices or hollows, such as in cliff faces (compare cremnophyte). (From Greek
chasma)
chimeraan individual composed of two or more genetically different tissues, most commonly as a result of a
graft and sometimes within the individual, by mutations and irregularities that occur during cell division.
chiropterophilouspollinated by bats.
chlorophylla green pigment in chloroplasts, essential for
photosynthesis.
chloroplastan
organelle present in plant cells that contains chlorophyll.
chlorosisabnormal lack or paleness of color in a normally green organ.
cilia (singular cilium, adjective ciliate) generally, hairs more or less confined to the margins of an organ, like eye-lashes; in motile cells, minute, hair-like protrusions which aid
motility.
circinatespirally coiled with the tip innermost; e.g. circinate vernation of the developing fronds of most ferns.
cladodea photosynthetic stem, often leaf-like and usually with foliage leaves either absent or much reduced; cf. phyllode.
classthe principal category for taxa in a rank between division and order.
clathratelatticed or pierced with apertures, like a cage.
clavateclub-shaped.
claw1. narrow, stalk-like basal portion of petal, sepal of bract.2. in
Melaleuca, the united portion of a stamen bundle.
cleistogamousof flowers that self-pollinate and never open fully, or self-pollinate before opening; cf. chasmogamous.
climbera plant growing more or less erect by leaning or twining on another structure for support, or by clinging with tendrils.
cline(adjective clinal) continuous morphological variation in form within a species or sometimes between two species.
cloneplants derived from the
vegetative reproduction of an individual, all having the same genetic constitution.
coalescentplant parts fused or grown together to form a single unit.
cochleariformconcave, spoon-shaped.
cochleatecoiled like a snail's shell.
coenobiumAn arranged colony of algae that acts like a single organism.
coenocyteA single cell with multiple nuclei, formed when nuclear division was not followed by
cytokinesis.
collenchymaA specialized tissue consisting of living cells with unevenly thickened
cellulose and
pectin cell walls that performs a support function in organs such as leaves and young stems that are composed of primary plant tissues.
colletera multicellular, glandular hair that usually produces a mucilaginous substance and is located on sepals, stipules, or petioles, or on nearby parts of stems; commonly found on plants in the order
Gentianales.
columellain flowering plants, the central axis of the
cone or fruit, e.g. in
Callitris.
column1. structure extending above ovary and incorporating the style and stamens; gynostemium; e.g. in orchids.2. in grasses, the lower, stouter, and usually twisted part of an awn, distinct from the slender upper part or bristle.
columnarshaped like a column.
commercial namea name often of no botanical standing and not governed by the ICNCP. The term generally applies to names such as Trademark Names, names covered by Plant Breeders Rights, Patents and Promotional Names; often used to enhance the sale of a plant.
commissurethe seam or face at which two carpels adhere.an assemblage, in nature, of plants that characteristically occur together.
compoundcomposed of several parts, for instance a leaf with leaflets, a gynoecium with several carpels, or an inflorescence made up of smaller inflorescences.
compound palmatea compound palmate leaf has leaflets that radiate from a central point (usually at the top of a petiole), like spread-out fingers radiating from the palm of a hand.
compressedflattened lengthwise, either laterally (from side to side) or dorsally (from front to back).
concolorousthe same colour throughout, uniformy coloured.
conduplicatetwo sides of a flat surface are folded along the midline to face each other. See also ptyxis, aestivation, and vernation.
conea fruit, usually
woody, ovoid to globular, including scales, bracts or bracteoles arranged around a central axis, e.g. in
gymnosperms, especially conifers and
Casuarina.
conflorescenceof an inflorescence when the overall structure substantially differs from that of the individual branches of the inflorescence, a rarely used term; e.g. the bottlebrush multiple-flower head of Callistemons.
connatefused to another organ (or organs) of the same kind; e.g. petals in a corolla tube; cf. adnate.
connectivethe part of an anther that connects the anther cells.
conniventcoming into contact or converging.
conspecificbelonging to the same species.
contiguousadjoining, touching, but not united.
contort(sepals and petals) a type of imbricate aestivation in which one side of each segment overlaps one of the adjacent segments and the other side is overlapped by the other adjacent segment. see:
convolutecontortedtwisted out of the normal shape.
convolute1. referring to the arrangement of floral or foliar organs in a bud when each organ or segment has one edge overlapping the adjacent organ or segment; a form of imbricate arrangement; contort.2. (leaves) a type of vernation in which one leaf is rolled up inside another.3. a type of vernation of two leaves at a node, in which one half of each leaf is exposed and the other half is wrapped inside the other leaf.
cordateheart-shaped, with the notch lowermost; of the base of a leaf, like the notched part of a heart.
coriaceousleathery; stiff and tough, but somewhat flexible.
cormfleshy, swollen stem base, usually underground, storing food reserves, with buds naked or covered by very thin scales; a type of rootstock. Adjectives derived from "corm" include "cormose" and "cormous".
corollacollective term for the petals of a flower.
corona(adjective: coronate) literally, crown
1. in flowering plants, ring of structures that may be united in a tube, arising from the corolla or perianth of a flower and standing between the perianth lobes and the stamens. The trumpet of a daffodil is a corona.
2. in grasses, a hardened ring of tissue surmounting the lemma in some species.
cortexOn a lichen, the cortex is the "skin", or outer layer of thallus tissue that covers the medulla Fruticose lichens have one cortex encircling the branches, even flattened, leaf-like forms; foliose lichens have different upper and lower cortices; crustose, placodioid and squamulose lichens have an upper cortex but no lower cortex; and leprose lichens lack any cortex.
corticolousGrowing on bark (compare with lignicolous, growing on wood with the bark stripped off.)
corymb(adjective corymbose) inflorescence with branches arising at different points but reaching about the same height, giving the flower cluster a flat-topped appearance.
costa (adjective costate) a rib.
costapalmatea costapalmate leaf has a definite costa (midrib), unlike the typical palmate or fan leaf, but the leaflets are arranged radially like in a palmate leaf.
cotyledonprimary leaf or leaves of an
embryo, becoming the seed leaf or leaves.
craspedodromouspinnate venation in which the secondary veins terminate at the margins, often as teeth.
crateriformIn the shape of a saucer or shallow cup; hemispherical or more shallow .
cremnophytea plant adapted to growing on, especially hanging from, cliff faces or crevices. (from Greek
kremao to hang,
kremnos cliff, overhanging rock or declivity) Compare chasmophyte
crenatewith blunt or rounded teeth,
scalloped.
crenulateminutely scalloped.
crispedfinely curled. A term generally applied to the edges of leaves and petals.
cristarque cella
sclereid which contains a
druse and has the
lignin deposited excentrically on the
cell wall to form a cup shape, or in cross
section, a ∪-shape.
crownsee canopy.
crossto make something interbreed; the act of hybridization.
cruciformcross-shaped.
crustaceoushard, thin and brittle.
crustoseforming a closely applied surface layer, forming a crust
cryptogamsferns,
bryophytes, algae and fungi (including lichenized fungi); 'lower plants'; plants producing spores, and without stamens, ovaries or seeds, literally plants whose sexual reproductive organs are not conspicuous cf. phanerogam.
cucullatefrom Latin
cucullus, a hood. Hood-like or hooded, commonly referring to the shape of leaves or petals. (Example:
Pelargonium cucullatum). Similarly derived terms include
cuculliform and
cuccularis.
culmin grasses, sedges, rushes, and some other
monocotyledons, an aerial stem bearing the inflorescence; strictly, from the base of the plant to the lowest involucral bract (or base of the inflorescence).
cultigena plant whose origin or selection is primarily due to intentional human activity.
cultivarthe term
cultivar is derived from cultivated variety and denotes an assemblage of cultivated plants clearly distinguished by one or more characters (morphological, physiological, cytological, chemical or other); when reproduced (sexually or asexually), the assemblage retains its distinguishing characters. A cultivar may arise in cultivation or be introduced from the wild. It is a variant of horticultural interest or value. Cultivar names are written with single quotation marks around them e.g. 'Blue Carpet', 'Alba'. All new names established after 1 January 1959, must be in common language (that is, not in Latin) but names established in Latin prior to this
date are retained in Latin form.
cultivar epithetthe defining part of a name that denominates a cultivar. Cultivars are designated by fancy (q.v.) epithets appended either to the scientific name or to the common name of the taxon to which they belong; they are not italicized but placed in single quotation marks, for example
Rubus nitidoides 'Merton Early'. 'Merton Early' is the cultivar epithet.
cuneatewedge-shaped; with straight sides converging at base. See Leaf shape.
cupulea cup-shaped structure composed of coalescent bracts, such as the cup of an
acorn.
cupularshaped like a cupule.
cupulatebearing cupules.
cupuliformnearly hemispherical, shaped like a cupola or dome.
cuspa pointed tip, hence cuspidate.
cuspidatetipped with a cusp, for instance leaf shape. Also tricuspidate – with three cusps etc.
cuticlea waterproofing layer covering the
epidermis of aerial plant surfaces, composed of the polymers
cutin, and/or cutan and waxes.
cuttinga piece of plant, usually an apical tip of shoot structure but may be root or leaf, cut from plant and used for vegetative propagation.
cyathiaplural of
cyathiumcyathiuman inflorescence of unisexual flowers surrounded by involucral bracts, esp. the flowers of
Euphorbia.
cyathophyllThe bract-like structure of a
Euphorbia on which the involucre sits, usually but not always occurring in twos. They may sometimes be brightly colored and confused with petals.
cylindricalrod-like and 2-3 times as long as wide, c.f. baculiform.
cyme(adjective cymose) inflorescence in which the main axis and all lateral branches end in a flower (each lateral may be repeatedly branched).
cypselaa dry, indehiscent, one-seeded fruit formed from an inferior ovary.
deciduousfalling seasonally, for instance bark, leaves, petals; compare persistent.
declinatecurving downwards, and then upwards at the tip. May be qualified, e.g. declinate-ascendant
decompounddivided to more than one level, as in bipinnate leaves for example, in which the leaflets of what otherwise would be a pinnate leaf, are themselves pinnately divided
decorticateto shed or peel off the outer bark of a tree.
decumbentwith branches growing horizontally on the ground, but turned up at the ends.
decurrentextending downwards beyond the point of insertion e.g. when the base of a leaf or a fungal gill is prolonged downwards along the stem in a raised line or narrow wing.
decussant= decussate. The usage
decussant is questionable and occurs rarely, probably as an error. The formally correct usage is
decussate.
decussateopposite, with successive pairs borne at right angles to the last; generally applied to the arrangement of leaves.
definiteof a constant number; e.g. twice as many stamens as the petals or sepals (or less), or an inflorescence ending in a flower or an aborted floral bud, typically a cymose inflorescence; cf. indefinite.
deflexedbent downwards; compare inflexed.
dehiscentbreaking open at maturity to release contents. Refers e.g. to the opening of fruits to release the seeds, of anthers to release the pollen and sporangia to release the spores. Contrast with indehiscent
deltoidwith the shape of the
uppercase Greek letter
Δ, i.e. like a more or less equilateral triangle. See Leaf shape.
dendroidtree-like, branching like a tree.
dentatetoothed. See Leaf margin.
denticulatefinely toothed, a diminutive form of dentate.
deserticolousinhabiting a desert.
determinatelimited, usually in growth.
diasporeA reproductive part of a plant, adapted for dispersal and for establishing new plants; a disseminule such as a seed, or specialised buds, branches, inflorescences or fruits.
dichasiuma cymose inflorescence with all branches below the terminal flower in regular opposite pairs; compare monochasium.
dichlamydeousperianth is divided into separate calyx and corolla. Compare to homochlamydeous, in which they are indistinguishable
dichotomousforking into two equal branches. This may result from an equal division of the growing tip, or may be sympodial, in which the growing tip is aborted and replaced. Typically refers to mode of branch growth, as in
Aloe dichotoma, but also to other organs, such as the thorns of various species of
Carissa (which morphologically are branches) and thalli or
hyphae of various algae and fungi.
dicotyledona flowering plant whose embryo has two (rarely more) cotyledons (seed leaves) (common usage: dicot.) compare
monocotyledon (common usage: monocot.).
digitatewith segments spreading from a common centre, like the fingers of a hand; see also palmate, palmatisect.
occurring in 2 different forms (in respect to shape and/or size), for example of stamens, fronds, leaves. See also
monomorphic (having a single form) and
polymorphic (many forms)
dioeciousof
vascular plants, when male and female reproductive structures develop on different individuals. cf. monoecious.
dioicousof bryophyte
gametophytes, when male and female reproductive structures develop on different individuals. cf. monoicous.
diploidwith two full sets of
chromosomes in the
nucleus of a
sporophyte cell, that is one set from each of the parental gametes. This is expressed symbolically as 2n, where n = the number of chromosomes in the haploid gametes.
diplostemonousstamens arranged in two whorls, with the outer whorl alternating with the petals, while the inner whorl is opposite the petals. Compare: obdiplostemonous.
disk (disc)a plate or ring of structures derived from the
receptacle, and occurring between whorls of floral parts. In some groups, especially
Sapindales, the nectary is in the form of a prominent disk. In daisies, the central part of the capitulum is a disk, hence flowers borne there are called disk flowers or florets.
discoidresembling a disc or plate, having both thickness and parallel faces and with a rounded margin. Also used to describe the flower head of Asteraceae where there are no ray florets, but only disc florets.
discolorousof leaves, with upper and lower surfaces of a different colour.
disjunctoccurring in widely separated geographic areas, distinctly separate; applies to a discontinuous range in which one or more populations are separated from other potentially interbreeding populations far enough as to preclude gene flow between them.
dissecteddeeply divided; cut into many segments.
distalremote from the point of origin or attachment; the free end; cf. proximal.
distichousarranged in two opposite rows (and hence in the same plane).
distinctseparate or free, not united.
distylythe condition in which the flowers of a species occur in two forms that differ only by the length of the style and stamens, and flowers of only one of these forms appear on any one plant. see:
heterostylydiurnalof the day; occurring or opening in the daytime.
divaricatewide-spreading.
divergentspreading in different directions, generally upward.
divisionthe term used for the rank below
kingdom in the taxonomic hierarchy.
domatia(singular domatium) Any hollow structure formed by a plant that is inhabited by animals such as ants or mites.
dorsalat the rear or back, facing away from the axis (abaxial) in a lateral organ or away from the substrate in a prostrate plant.
dorsifixedattached at or by the back, e.g. anthers on a filament.
dorsiventralhaving structurally different upper and lower surfaces, e.g. some leaves.
drip tipa long, narrow, caudate or acuminate extension at the tip of a leaf or leaflet.
drupea succulent fruit formed from one carpel; the single seed is enclosed by a stony layer of the fruit wall; kernel; e.g. peaches, olives.
drupeleta drupe, usually small, formed from one of the carpels in an apocarpous flower. Drupelets usually form a compound fruit, as in
Rubus, but they may become widely separated, as in
Ochna.
drusea globular mass of
calcium oxalate crystals, usually with the crystals radiating from an
organic core.
-eaeThe suffix added to the stem of a generic name to form the name of a
tribe: for instance,
Aster →
Astereae.
ebracteatewithout bracts. Similarly ebracteolate.
ecological amplitudethe range of environmental conditions in which an organism can survive.
edaphicInfluenced by or of the soil.
elaiosomeoily body attached to the seed.
elephophilya form of pollination whereby pollen or spores are distributed by the feet of elephants, as in
Rafflesia arnoldiiellipsoida 3-dimensional shape, elliptical in all sections through the long-axis.
elliptical (elliptic)planar, shaped like a flattened circle, symmetrical about both the long and the short axis, tapering equally both to the tip and the base;
oval.
emarginatenotched at apex (notch usually broad and shallow).
embryoyoung plant contained by a seed.
emergenta plant taller than the surrounding vegetation or, for a water-based plant, one whose leaves and flowers are above the water.
enantiostylythe condition in which the gynoecium protrudes laterally, to the right (dextrostyly) or to the left (sinistrostyly) of the androecium. example:
Senna.
endemichaving a natural distribution restricted to a particular geographic region; cf. native.
endocarpthe innermost layer of the wall of a fruit; in a drupe, the stony layer surrounding the seed.
endodermisthe innermost layer of the cortex of vascular plant roots, also present in the stems of
pteridophytes. The radial walls are impregnated with
suberin to form a permeability barrier known as the
Casparian strip.
endophloeodalendophloic
endophloic(
synonym – endophloeodal) of crustose lichens, having the thallus growing within rather than on the bark of trees, Compare with epiphloedal or corticolous growing on the surface wood or bark; also cf. endolithic growing within rock, not wood
endosperm1. (angiosperms) a nutritive tissue surrounding the embryo of the seed, usually triploid, originating from the fusion of both polar nuclei with one
gamete after the fertilization of the egg.2. (gymnosperms) the prothallium within the embryo sac.
ensiformshaped like the blade of a sword.
entire1. not divided.2. (of a margin) having a smooth margin, not lobed or toothed (it may be wavy or scalloped).
entomophilya form of pollination whereby pollen or spores are distributed by
insects.
ephemeralshort-lived. See also caducous.
epicalyxan involucre resembling an outer calyx; e.g. as seen in
Hibiscus.
epicarpthe outer layer of the wall of a fruit, i.e. the 'skin'.
epicormicsaid of buds shoots or flowers developing from the old wood of trees, especially after injury or fire.
epicotylthe part of the plant axis or stem between the cotyledonary node and first foliage leaves.
epicuticular waxa layer of crystalline or amorphous
wax deposited on the surface of the plant cuticle.
epidermisan organ's outermost layer of cells, usually only one cell thick.
epigynousborne on the ovary; describes floral parts when attached above the level of the ovary and arising from tissue fused to the ovary wall; cf. hypogynous, perigynous.
epilithicgrowing on stone; compare lithophytic, a plant growing on stone.
epinecralDead tissue (necral) above the surface of the cortex of a lichen.
epipetalousof stamens that are attached to the petals.
epiphloedalGrowing on bark; cf. endophloedal – growing inside, not on, the bark; cf. epilithic – growing on rock, not bark.
epiphyticLiving on the surface of a plant; cf. lithophytic.
epitepalousof stamens that are attached to the tepals.
epiphyte(adjective epiphytic) one plant growing on another without deriving nourishment from it (in other words, not parasitic); compare parasite. Loosely, and incorrectly, applied to plants that are not
terrestrial (they may grown on various inorganic or organic surfaces), and often to orchids, which are rock-dwelling (and therefore strictly lithophytic).
epithetthe adjectival component in a binomial; final word or combination of words in a name of more than one word (other than a term denoting rank) that denominates an individual taxon.
epizoochorySeed dispersal by sticking on the outside of vertebrate animals.
epruinosenot pruinose
equitantof a leaf when folded lengthwise and clasping another leaf.
erectupright, more or less perpendicular to the ground or point of attachment. Compare
patent (spreading). Erecto-patent, between erect and patent.
ericoidwith leaves like those of the European heaths (
Erica), small and sharply pointed.
erosewith the margin irregular as though nibbled or worn away.
even-pinnatehaving an even number of leaflets in a compound leaf, = paripinnate.
evergreennot deciduous, having leaves all the year round.
exin nomenclature, indicating that the preceding author proposed the name but did not legitimately publish it, and that the succeeding author referred to the first author when legitimately publishing the name. See Author citation (
botany).
exocarpthe outer layer of the pericarp, often the skin of fleshy fruits.
exotestathe outer layer of the testa (seed coat). It is derived from the outer
integument of the ovule.
exoticnot native; introduced from another region or country.
exsertedprojected beyond, e.g. the stamens beyond the corolla tube.
exstipulatewithout stipules.outside the stamens or androecium, usually referring to the location of a nectary disk.
extrorseof anther
locules, opening towards the outside of the flower; cf. introrse, latrorse.
F1 hybrida single cross; a plant breeding term for the result of a repeatable cross between two pure bred lines.
F2 hybrida plant breeding term for the result of a plant arising from a cross between two F1 hybrids; may also refer to
self-pollination in a population of F1 hybrids.
fabiformshaped like a
kidney-bean.
facultativeof parasites, optional; compare
obligate.
falcatecurved like the blade of a
scythe.
familya formal
group of one or more genera with features and/or ancestry in common; the term for the principal rank between order and genus.
farinaceouspowderiness that is mealy
fascicle(adjective fasciculate) cluster, e.g. a tuft of leaves all arising from the same node.
fasciculatebranching in a cluster like a bundle of sticks or needles, having fascicles.
faveolatehoneycombed. With regular, angled pits. Compare foveolate.
faucalpertaining to the fauces; located in the throat of a calyx or corolla.
faucesthe throat of a calyx or corolla; the conspicuously widened portion between the mouth and the apex of the tube. In
Boraginaceae, the site of distinctive appendages.
feltedcovered with very dense, interlocked and matted hairs with the appearance or texture of felt or woollen cloth.
fenestratewith translucent areas. See also perforate, with holes.
ferruginousrust-colored.
fertilecapable of producing fruit; of flowers when they produce seed or of anthers containing pollen.
fertilizationunion of male and female gametes.
fiber1. a fiber cell.2. any flexible, strong, stringy, and very elongate structure.
fiber cella type of cell that is found in sclerenchyma, it is much elongated and dies soon after an extensive modification of its cell wall. The cell wall is usually thickly lignified, but is sometimes gelatinous.
filament1. stalk of a stamen2. thread, one or a few cells thick.
filamentousconsisting of filaments or fibres, hairlike.
filiformthread-like.
e.g. stamen filaments, or leaf shapes.
fimbriaslender hair-like process (plural: fimbriae)
fimbriatefringed.
fissurea split or crack, often referring to fissured bark. also, a line or opening of
dehiscence.
fistuleA tube-shaped cavity.
fistuloseHollow, usually applied to a tube-shaped cavity as in a
reed.
flabellatefan-shaped.
flaccidlimp; tending to wilt; compare turgid.
flexuous (flexuose)bent alternately in different directions; zig-zag.
floccosewith a soft and woolly covering of hairs.
flora1. all the plants growing in a certain region or country.2. an enumeration of them, generally with a guide to their identification (e.g. the present volume, the Flora of Victoria, the Flora of New South Wales and so on). In this case 'flora' is written with a capital F.
floral envelopeSee perianth.
floral leavesthe upper leaves at the base of the flowering branches.
floral diagramgraphical means to describe the flower structure, a schematic cross-section through a young flower.
floral formulatextual means to describe the flower structure using numbers, letters and various symbols.
floral tubean imprecise term sometimes used as a
synonym of
hypanthium or of corolla tube or of calyx tube.
floretliterally a small flower, but usually refers to the individual true flowers clustered within an inflorescence, particularly in inflorescences of the daisy and grass families.
flowerthe sexual reproductive structure of the Angiosperms, typically with a gynoecium, androecium, perianth and an axis.
foliatepreceded by a number: having a certain number of leaflets; for example, 3-foliate, "having three leaflets"
foliicolousgrowth
habit of certain lichens, algae, and fungi that prefer to grow on the leaves of vascular plants.
folliclea dry fruit formed from one carpel, splitting along a single
suture, to which the seeds are attached; cf. pod (of
legume).
foliolea small leaf-like appendage on the front or back.
folioseleaflike, flattened like a leaf
forbany non-woody flowering plant that is not a grass, sedge, or rush.
forestvegetation dominated by trees with single trunks (including closely arranged trees with or without an understorey of shrubs and herbs).
forma (in common usage, form)a taxonomic category subordinate to species and within the taxonomic hierarchy, below variety (varietas), usually differentiated by a minor character.
foveolatewith regular tiny pits. Compare faveolate.
freenot united with others organs of the same type; not attached at one end.
free centralof
placentation,
ovules attached to a free-standing column in the centre of a unilocular ovary.
fronda leaf of a fern,
cycad or palm.
frutescentshrub-like (fruticose) or becoming shrub-like
fruticoseshrubby, with the branching character of a shrub
fruitseed-bearing structure in angiosperms formed from the ovary, and sometimes associated floral parts, after flowering.
fugacious disappearing, falling off, or withering; compare persistent and caducous.
funicle (funiculus) the stalk of an ovule.
funnelformwith a form gradually widening from the base to apex; funnel-shaped.
furcateforked, usually applied to a terminal division; with two long lobes.
fusedjoined together.
fusiformrod-shaped and narrowing gradually from the middle towards each end; spindle-shaped.
galbulus(in gymnosperms) a fleshy cone (megastrobilus); chiefly relates to those borne by junipers and cypresses and often mistakenly called berries.
gametea cell or nucleus that fuses with another of the opposite sex in sexual reproduction.
gametophytethe haploid multicellular phase in the
alternation of generations of plants and algae that bears gametes. In bryophytes the gametophyte is the dominant vegetative phase; in ferns and their allies it is a small free-living plant known as the prothallus; in gymnosperms and angiosperms the gametophytes are reduced to microscopic structures dependent on the
sporophyte, male gametophytes contained in pollen grains and females contained within the ovules.
gene poolthe range of genetic variation found in a population.
genus(plural genera) a group of one or more species with features or ancestry (or both) in common. Genus is the principal category of taxa intermediate in rank between family and species in the nomenclatural hierarchy.
generic namethe name of a genus, for example
Acacia,
Eucalyptus.
genotypethe genetic make-up of an individual.
geophilousgrowing or rooting in the ground.
germination1. of seeds, describing the complex sequence of physiological and structural changes that occur from resting to growth stage.2. of a pollen grain; production of a pollen tube when contacting a stigma receptive to it.3. of a
spore of fungi/bacterium; change of state – from resting to vegetative.
gibbous (gibbose)when part of an organ is swollen; usually with a pouch-like enlargement at base.
glabrescentbecoming glabrous, almost glabrous.
glabrouswithout surface ornamentation such as hairs, scales or bristles; (in lichenology) having no
indumentum.
glanda secretory structure within or on the surface of a plant.
glandular hairhairs tipped with a gland.
glaucouswith a whitish bloom, blue-green in colour; e.g. the surface of the young leaves of many eucalypts.
globose (globular)spherical. See also
subglobose.
globuloseapproximately spherical.
glochida barbed hair or bristle, e.g. the fine hairs in
Opuntia.
glumesbracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost organs of a spikelet (there are usually 2 but 1 is sometimes reduced; or rarely, both are absent).
glutinoussticky.
graft1. of a plant, the artificial union of plant parts.2. a plant shoot suitable for grafting; loosely means a scion, #sucker or branch.
graft chimaera (sometimes graft hybrid)a taxon whose members consist of tissue from two or more different plants in intimate association originated by grafting. The addition sign "+" is used to indicate a graft-chimaera either as a part of a formula (e.g.
Crataegus monogyna +
Mespilus germanica), or in front of an abbreviated name (e.g. +
Crataegomespilus 'Dardari'). The nomenclature of graft hybrids is governed by the
International Code of Nomenclature for Cultivated Plants.
granularof a surface, covered with small rounded protuberances.
grassa plant belonging to the family
Poaceae.
grasslandlow vegetation dominated by grasses.
groundcover1. of dense vegetation that covers the ground.2. a term applied to describe a plant that covers the soil surface so densely that it smothers all beneath it.
Groupa formal category equivalent to or below the rank of genus. It distinguishes:
1. an assemblage of two or more cultivars within a species or hybrid.
2. plants derived from a hybrid in which one or more of the parent species is not known or is of uncertain origin.3. a range of cultivated plants of a species or hybrid which may exhibit variation but share one or more characters, which makes it worth distinguishing them as a unit.
guard celleach of the two cells that surround the
stoma and control gas exchange between the apoplast of the plant and the external air.
guttate, guttatuswith droplet-shaped spots. Compare punctate, maculate.
guttationthe secretion of liquid water from uninjured plant parts. See hydathode.
guttulatewith or appearing to be spotted with oil droplets; (of spores) having oil droplets inside
gymnosperma seed-bearing plant with unenclosed ovules borne on the surface of a
sporophyll; includes, among others, conifers,
Ginkgo,
Gnetum and
cycads. From
gymno = naked, exposed; compare
angio = covered, enclosed.
gynobasicof a style, arising near the base of the gynoecium, e.g. between the lobes of the ovary.
gynodioeciousof a species, with some plants bearing only bisexual flowers and others bearing only female flowers.
gynomonoeciousof a species, with bisexual flowers and female flowers on the same plant.
gynoeciumfemale parts of flower; the collective term for the carpels of a flower whether united or free; cf. pistil; androecium. Abbreviation: G. For instance
G indicating superior ovary. G(5) indicates having 5 fused carpels.
gynophorestalk supporting the gynoecium (above the level of insertion of the other floral parts).
habitthe general external appearance of a plant, including size, shape, texture and orientation.
habitatthe place where a plant lives; the environmental conditions of its home.
haftera flat attachment that forms when the thallus of a fruticose or foliose lichens comes in contact with a substrate, different from rhizines and hapters.
haira single elongated cell or row of cells borne on the surface of an organ.
half-inferiorof ovary, partly below and partly above the level of attachment of the other floral parts; compare inferior, superior.
halonatehaving a transparent coating, or being of a spores outer layer.
halophytea plant adapted to living in highly saline habitats; a plant that accumulates high concentrations of salt in its tissues.
hand-pollinationthe controlled act of pollination that excludes the possibility of open-pollination.
haploidwith one set of chromosomes, e.g. the complement of chromosomes in each of the cells of the gametophyte, the nucleus of a gamete and the spores. This is expressed symbolically as n, where n = the gamete number of chromosomes.
hapteran attachment that may form when a foliose lichen thallus comes in contact with a substrate.
hastatetriangular in outline, the basal lobes pointing outwards, so that the base appears truncate; may refer only to the base of a leaf with such lobes; cf. sagittate which refers to basal lobes pointing backwards.
haustoriumin parasitic plants, a structure developed for penetrating the host's tissues.
headsee capitulum, a pseudanthium.
heathlandvegetation dominated by small shrubs which usually have ericoid leaves.
helicoidcoiled; of a cymose inflorescence, when the branching is repeatedly on the same side (the apex is often recurved); cf. scorpioid.
herba vascular plant that does not develop a woody stem; e.g. a violet.
herbaceousnot woody; usually green, and soft in texture.
herbariuma collection of preserved, usually dried, plant material. Also a building in which such collections are stored.
hermaphroditeSynonym of bisexual.
heteroblastichaving parts, especially leaves, that are distinctly different between the
juvenile and adult stages.
heteromorphicof 2 or more distinct morphologies (e.g. of different size and shape).
heterostylythe condition of a species having flowers with different style and stamen lengths, but with all the flowers of any one plant being identical. see:distyly
hilumthe scar on a seed coat where it separates from its stalk (funicle).
hipthe fruit of a rose.
hippocrepiformhorseshoe-shaped.
hirsutebearing coarse, rough, longish hairs. See Indumentum.
hispidhaving long erect rigid hairs or bristles, harsh to touch.
hoarycovered with a greyish to whitish layer of very short, closely interwoven hairs, giving a frosted appearance.
holotypea type chosen by the author of a name; cf. a lectotype, which is chosen by a later author.
homochlamydeousperianth not divided into calyx and corolla. Compare to dichlamydeous, in which they are separate
hort.(never capiltalised) of gardens, an author citation used in two ways:
as a name misapplied by gardeners
2. as an invalid name derived from horticultural writings of confused authorship.
hyalinetranslucent; usually delicately membranous and colourless.
hybrida plant produced by the crossing of parents belonging to two different named groups, e.g. genera, species, varieties,
subspecies, forma and so on; i.e. the progeny resulting within and between two different plants. An
F1 hybrid is the primary product of such a cross. An F2 hybrid is a plant arising from a cross between two F1 hybrids (or from the self-pollination of an F1 hybrid).
hybrid formulathe names of the parents of a hybrid joined by a multiplication sign, e.g.
Cytisus ardonoi × C. purgans.
Hydrophilya form of pollination whereby pollen is distributed by the flow of waters.
hypanthiumA tube or cup-like structure in a flower that includes the bases of sepals, petals, and stamens, and may or may not be connected (adnate) to the ovary.
hyper-resupinate1. In botany, describing leaves or flowers that are in the usual position, but are borne on a petiole or pedicel, respectively, that is twisted 360 degrees. The term is used to describe organs, such as orchid flowers, that are usually resupinate. compare: #resupinate
hypocarpiuman enlarged fleshy structure that forms below the fruit, from the receptacle or hypanthium.
hypocotylof an embryo or seedling, the part of the plant axis below the cotyledon and node, but above the root. It marks the transition from root to stem development.
hypocrateriformsalverform.
hypogynousborne below the ovary; used to describe floral parts inserted below the ovary's level of insertion; cf. epigynous, perigynous.
hypothallusThe hypothallus is the outgrowth of hyphae from under the margin of the thallus of a crustose lichens, connecting the island-like areoles into a single lichen.
hysteranthous (histeranthous)new leaves appear after flowering. See also
proteranthous and
synanthousidioblasta cell, especially of a leaf, differing markedly from surrounding cells. They often synthesise specialised products such as crystals.
illegitimate name (nomen illeg.)a name not abiding by the rules of the botanical Codes, e.g. later homonyms, cultivars that have been Latinised after 1 Jan 1959; cultivar names with more than 10 syllables or 30 letters; cultivar names that use confusing names of other plants, e.g. Camellia 'Rose'.
imbricateoverlapping each other; of perianth parts, edges overlapping in the bud (the convoluted arrangement is a special form of imbrication).
imparipinnatea pinnate leaf with an odd number of pinnae (terminated by a single leaflet); compare paripinnate.
inin nomenclature, where the preceding author published the name in an article or book, authored or edited by the succeeding author.
-inaeThe suffix added to the stem of a generic name to form the name of a subtribe: for instance, Corydalinae from
Corydalis +
-inae.
inbreedingthe production of offspring between closely related parents leading to a high degree of similarity; self-fertilization is the most intense form of inbreeding.
incertae sedisof unknown taxonomic affinity, relationships obscure.
incisedcut deeply and (usually) unevenly (a condition intermediate between toothed and lobed).
includedenclosed, not protruding; for example stamens within the corolla.
incurvedbent or curved inwards; of leaf margins, when curved towards the adaxial side.
ined.abbreviation of Latin
inedita, an unpublished work. Used to indicate that a
botanical name appeared only in a manuscript that was not published, so the name is invalid.
indefinitevariable in number; numerous; e.g. more than twice as many stamens as petals or sepals, or when an inflorescence is not terminated by a flower (and continues growing); cf. definite.
indehiscentnot opening in any definite manner at maturity; usually referring to fruit. Contrast with dehiscent.
indeterminateunlimited, usually in growth.
indigenousnative to the area, not introduced, and not necessarily confined to the region discussed or present throughout it (hardly distinct from ‘native’ but usually applied to a smaller area). For example, the Cootamundra Wattle is native to Australia but indigenous to the Cootamundra region of southern New South Wales; cf. endemic.
indumentuma collective term for a surface covering of any kind of
trichomes, e.g. hairs, scales.
induplicatefolded upwards, or folded with the two adaxial surfaces together.
indusium1. a membrane covering the sporangia of some ferns.2. a cup enclosing the stigma in
Goodeniaceae.
inferiorof an ovary, at least partly below the level of attachment of other floral parts; compare superior.
inflatedswollen, like a bladder.
inflexedbent sharply upwards or forwards; compare deflexed.
inflorescenceseveral flowers closely grouped together to form an efficient structured unit; the grouping or arrangement of flowers on a plant.
infraspecificdenotes taxonomic ranks below species level, for example subspecies.
infragenericdenoting taxonomic ranks below the genus level, for example, subgenera, sections, and
series.
infructescencethe grouping or arrangement of fruits on a plant.
wikt:infundibular (infundibuliform)funnel-shaped, for example in the corolla of a flower.
inrolledrolled inwards.
insectivorouscatching, and drawing nutriment from, insects.
insertion, point ofthe point at which one organ or structure (such as a leaf) is joined to the structure which bears it (such as a stem).
insertedgrowing out from
integumentin general, any covering, but especially the covering of an ovule.
intercalary(e.g. of growth) occurring between the apex and the base of an organ
intercalary meristema meristem located between the apex and the base of an organ
interjugary glandsin pinnate leaves, glands occurring along the leaf
rachis between the pinnae (occurring below the single, and often slightly larger, gland at or just below the insertion of the pinnae); cf. jugary.
internodethe portion of a stem between two nodes.
interpetiolarof stipules, between the petioles of opposite leaves, e.g in
Rubiaceae.
intramarginalinside but close to the margin, for example a vein in a leaf.
intrastaminalinside the stamens or androecium, usually referring to the location of a nectary disk.
introrseof anther locules, with opening towards the centre of flower (at least in bud); cf. extrorse, latrorse.
invaliduse of names not validly published according to the Code; i.e. they are not strictly 'names' in the sense of the International Code of Botanical Nomenclature.
involucreA structure surrounding or supporting, usually a head of flowers. In Asteraceae, it is the group of phyllaries (bracts) surrounding the inflorescence before opening, then supporting the cup-like receptacle on which the head of flowers sits. In
Euphorbiaceae it is the cuplike structure that holds the
nectar glands, nectar, and head of flowers, and sits above the bract-like cyathophyll structure. Involucres occur in
Marchantiophyta, Cycads, fungi, and many other groups.
involuterolled inwards, for example when the margins of a leaf are rolled towards the adaxial (usually upper) surface; compare revolute.
iridescentwith a reflective coloured sheen produced by
structural coloration, as in the speculum of the mirror orchid
Ophrys speculum.
irregularcannot be divided into two equal halves through any vertical plane. See also asymmetrical, compare zygomorphic, actinomorphic, regular.
isidiumA warty of club-like structure in some lichens that breaks off and forms new lichens without sexual reproduction. Isidia are dispersed by mechanical means, compared to soredia, which are dispersed by wind.
isobifacial(of flat structures, especially leaves) with both surfaces similar, usually referring to cell types or to the number and distribution of stomata.
isomerousHaving an equal number of parts in the whorls.
isotomichaving branches of equal diameter, compare to anisotomic.
jointa node or junction of two parts; articulation.
jugaryof glands, gland occurring on the
rachis of a bipinnate leaf at the junction or attachment of pairs of pinnae or pinnules, as in some
Acacia species; cf. interjugary.
juvenile leavesformed on a young plant and different in form from the adult leaves.
K, K+, K-In lichenology, "K" is the abbreviation for the outcome of a test in which a 10% solution of potassium hydroxide (KOH — hence "K") is placed on lichen tissues. Color change is noted by "K-" for none, and K+ for a yellow to red or purple color.
keel(adj. keeled), a prominent longitudinal ridge like the keel of a boat, e.g. the structure of the corolla formed by the fusion of the lower edge of the two abaxial anterior petals of a flower in the
Fabaceae.
kernelsee drupe.
key innovationa novel phenotypic trait that allows subsequent
evolutionary radiation and success of a taxonomic group.
kingdomthe highest generally employed category of the taxonomic hierarchy, above that of division (phylum). The Plant Kingdom includes vascular plants, bryophytes and
green algae and is also known as the clade
Viridiplantae.
labellumlip; one of three or five petals which is (usually) different from the others, e.g. in Orchidaceae and
Stylidiaceae.
labiatelipped; where a corolla is divided into two parts, called an upper and lower lip, the two resembling an open mouth with lips.
laceratejagged, as if torn.
laciniaIn foliose lichens, a linear to elongate lobe, usually arising from or at the end of a larger lobe
laciniateOf lobes – with ends irregularly divided into deeply divided, narrow, pointed segments; Of margins – deeply divided into pointed segments in an irregular manner.
lacunaAn empty space, hole, cavity, pit, depression, or discontinuity.
lamellaa thin, plate-like layer. (plural lamellae; adjective lamellate – composed of an assemblage of many layers)
laminathe blade of a leaf or the expanded upper part of a petal, sepal or bract.
laminalof, or pertaining to, the upper surface, such as the cortex of a lichen.
lanceolatelonger than broad, narrowly ovate, broadest in the lower half and tapering to the tip, like a lance or spear head; (sometimes, and incorrectly, used to mean narrowly elliptic).
lateralattached to the side of an organ, e.g. leaves on a stem.
latexa milky fluid that exudes from such plants such as spurges, figs and dandelions.
laticiferouslatex-bearing, producing a milky juice.
latrorsea type of anther dehiscence in which the anthers open laterally toward adjacent anthers. cf. introrse, extrorse.
lauroidresembling
Laurus, the laurel genus, particularly its leaves.
laxloose, not compact. Of bundles of hyphae in lichens – not stiff and not adglutinate.
leafan outgrowth of a stem, usually flat and green; its main function is food manufacture by
photosynthesis. Abbreviation: lvs.
leaf gapa
parenchymatous area in the
stele above (distal to) a leaf trace.
leaf scara healing layer forming on the stem where the leaf has fallen off.
leaf tracea
vascular bundle connecting the
stele to a leaf.
leafletsthe ultimate segments of a compound leaf.
lecanorineof lichens, having apothecia with rims of tissue similar to the tissue of the thallus, as in the genus
Lecanoralegume1. a fruit characteristic of the family
Fabaceae, formed from one carpel and either dehiscent along both sides, or indehiscent.2. a crop species in the family Fabaceae.3. a plant belonging to the Fabaceae family).
lemmathe lower of 2 bracts enclosing a grass flower.
lenticelTypically lens-shaped (
lenticular) porous tissue in bark with large intercellular spaces that allows direct
exchange of gases between the internal tissues and atmosphere through the bark.
lenticular1. lens-shaped.2. covered in lenticels
lepidotecovered with small scales.
leprosepowdery
lianaa woody climbing plant, rooted in the ground (liane is also used).
lianea woody climbing plant, rooted in the ground. See also liana.
lichenicolousgrowing on or in lichens, often but not necessarily as parasites
ligneouswoody
lignumDead wood, typically in the context of a substrate for lichens.
lignicolousGrowing on wood tissue after bark as fallen or been stripped off (compare to corticolous)
lignotubera woody swelling of the stem below or just above the ground; contains adventitious buds from which new shoots can develop, e.g. after fire.
ligulate1. bearing a
ligule.2. strap-shaped.
ligule1. small membranous appendage on the top of the sheath of grass leaves.2. a minute adaxial appendage near the base of a leaf, e.g. in
Selaginella.3. extended, strap-like corolla of some daisy florets.
linea, line, British line, Paris linevarious pre-metric units somewhat larger than 2 mm, used in botany into the 20th century. See Line (unit) and Paris line.
linearvery narrow in relation to its length, with the sides mostly parallel. See Leaf shape.
lithophytica plant growing on rocks; an epilithic plant.
lobepart of a leaf (or other organ), often rounded, formed by incisions to about halfway to the midrib.
loculicidalof a fruit, when it dehisces through the centres of loculi; cf. septicidal.
loculea chamber or cavity containing seeds within an ovary, pollen within an anther or spores in a
sporangium.
lodiculeone of 2 or three minute organs at the base of the ovary of a grass flower, representing parts of a strongly reduced perianth.
lomentuma pod-like indehiscent fruit that develops constrictions between the segments and at maturity breaks into one-seeded segments.
longicidal(anthers) opening lengthwise by longitudinal slits. compare: poricidal
lunatecrescent-shaped.
lyratelyre-shaped; deeply lobed, with a large terminal lobe and smaller lateral ones.
maculatespotted, marked with spots.
Malesiaa biogeographic region comprising Malaysia, Indonesia, New Guinea, and the Philippines.
malleegrowth habit in which several woody stems arise separately from a lignotuber; a plant with such a growth habit, e.g. many Eucalyptus species; vegetation characterized by such plants.
mangrovea shrub or small tree growing in salt or brackish water, usually characterized by pneumatophores. Tropical coastal vegetation characterized by such species.
marginthe edge, as in the edge of a leaf blade.
marginaloccurring at or very close to the margin.
marsha waterlogged area; swamp.
mastedible fruit and nuts produced by woody species of plants, i.e.
acorns and
beechmast, that wildlife species and some domestic animals consume.
mealycovered with coarse, floury powder.
medulla1. In a lichen, the typically undifferentiated tissue underneath the cortex of the thallus, or between the upper and lower cortex if both are present. The medulla is analogous to the tissues underneath the epidermis (skin) of a leaf. The uppermost region commonly contains most of the photobionts.2.
pith. See also
medullary rays in wood.
megasporethe larger of two kinds of spores produced by a heterosporous plant giving rise to the female gametophyte; compare
microspore.
megastrobilusthe larger of two kinds of cones or strobili produced by gymnosperms, being female and producing the seeds; compare microstrobilus.
membranousthin, translucent and flexible, seldom green.
mericarpone segment of a fruit (a
schizocarp) that splits at maturity into units derived from the individual carpels, or a carpel, usually 1-seeded, released by the break-up at maturity of a fruit formed from 2 or more joined carpels.
meristeman actively dividing tissue.
mesicmoist, avoiding both extremes of drought and wet; pertaining to conditions of moderate moisture or water supply; applied to organisms (vegetation) occupying moist habitats.
mesocarpthe fleshy portion of the wall of a succulent fruit inside the skin and outside the stony layer (if any), surrounding the seed(s); sarcocarp.
mesomorphicsoft and with little fibrous tissue, but not succulent.
mesophyll1. mesophyll tissue, photosynthetic tissue of a leaf, the central tissues between the upper and lower epidermis.2. in ecology, the blade of a leaf or leaflet that has a surface area 4500–18225 mm
2; A plant, or vegetation, that has mesophyll (sized) leaves.
mesophyllous(of vegetation) of moist habitats and having mostly large and soft leaves.
mesophytea plant thriving under intermediate environmental conditions of moderate moisture and temperature, without major seasonal fluctuations.
microsporethe smaller of two kinds of spores produced by a heterosporous plant; compare megaspore.
microstrobilusthe smaller of two kinds of cones or strobili produced by gymnosperms, being male and producing the pollen; compare megastrobilus.
midribthe central, and usually most prominent, vein of a leaf or leaf-like organ; midvein.
midveinsee midrib.
monada single individual that is free from other individuals, not united with them into a group. The term is usually used for pollen to distinguish single grains from tetrads or polyads.
moniliformresembling a string of beads.
monocarpicflowering and setting seed only once before dying. See also semelparous, semelparity
monochasiuma cymose inflorescence with the branches arising singly; cf. dichasium.
monocotsabbreviation of monocotyledons.
monocotyledona flowering plant whose embryo has one cotyledon (seed leaf); compare dicotyledon.
monoeciousof vascular plants, hermaphrodite, with all flowers bisexual; or with male and female reproductive structures in separate flowers but on the same plant; or of an inflorescence that has unisexual flowers of both sexes; cf. dioecious.
monoicousof bryophyte gametophytes, hermaphrodite, bisexual, when both male and female reproductive structures develop on the same individual. cf. dioicous.
monographof a group of plants, a comprehensive treatise presenting an analysis and synthesis of taxonomic knowledge of that taxon; the fullest account possible (at the time) of a family, tribe or genus. It is generally worldwide in scope and evaluates all taxonomic treatments of that taxon including studies of its evolutionary relationships with other related taxa, and cytological, genetic, morphological, palaeobotanical and ecological studies. The term is often incorrectly applied to any systematic work devoted to a single taxon. Compare revision.
monomorphicof one type, rather than several. See also dimorphic (two types) and polymorphic (many types)
monophyllousHaving a single leaf.
monopodiala mode of stem growth and branching in which the main axis is formed by a single dominant meristem.
monostromaticBeing a single cell thick, as in the alga
Monostroma.
monotypiccontaining only one taxon of the next lower rank, e.g. a family with only one genus, or a genus that includes only a single species.
morphologythe shape or form of an organism or part thereof.
mucroDiminutive: mucronule. A sharp, short point, generally at the tip of a leaf or the tip of the midrib of a compound leaf.
mucronateterminating in a mucro.
multiple fruita cluster of fruits produced from more than one flower and appearing as a single fruit, often on a swollen axis, as in
Moraceae; cf. aggregate fruit.
muricatecovered with short hard protuberances.
mutationan abrupt and inexplicable variation from the norm, such as the doubleness in flowers, changes in colour, or
habit of growth.
mycobiontThe fungal component of a lichen (compare to photobiont.
myceliumThe "vegetative" (nonreproductive) part of a fungus, mostly composed of aggregations of hyphae. It functions in substrate decomposition and absorption of nutrients.
mycobiontThe fungal component of a lichen (compare to photobiont.
mycorrhizaone of several types of symbiotic association between a fungus and the roots of a plant.
mycotropha plant that obtains most or all of its carbon, water and nutrients by associating with a fungus.
nativenaturally occurring in an area, but not necessarily confined to it; cf. endemic.
natural hybrida hybrid taxon produced by chance in the wild.
naturaliseddescribing a plant, introduced from another region, that grows and reproduces readily in competition with the natural flora.
nectara (usually sweet) fluid produced by the flowers of many plants, collected by bees and other insects.
nectary(adjective nectariferous) a specialized gland that secretes nectar.
neophytea plant that was recently introduced to a geographic area; cf. archaeophyte.
nervesynonym of vein.
nodethe part of a stem where leaves or branches arise.
nomen conservandum(Latin) a conserved name, usually a name that became so much better known than the correct name, that a substitution was made.
nomen illegitimum(Latin), a name that is either superfluous at its time of publication because the taxon to which it was applied already has a name, or the name has already been applied to another plant (a homonym).
nomen invalidum(Latin, see valid publication) a name that is not validly published, and technically is therefore not a botanical name. (Abbreviation: nom. inval.)
nomen nudum(Latin) a name not published in accordance with the
International Code of Nomenclature for algae, fungi, and plants, usually without a diagnosis or description of the entity to which it applies, and without reference to either; such a name should not be used.
nomenclaturethe naming of things; often restricted to the correct use of scientific names in
taxonomy; a system that sets out provisions for the formation and use of names.
noxiousof plants, containing harmful or unwholesome qualities. Applied in conjunction with 'weed' to specifically describe a plant which legislation deems harmful to the environment. Each state and territory in Australia has specific legislation governing noxious weeds.
nucellusthe tissue of the ovule of a seed plant that surrounds the female gametophyte. It is enclosed by integuments and is not of epidermal origin.
numerousStamens are described as numerous when there are more than twice as many as sepals or petals, especially when there is no set number of them.
nuta hard, dry, indehiscent fruit, containing only one seed.
nutleta small nut, one of the lobes or sections of the mature ovary of some members of the
Boraginaceae,
Verbenaceae, and
Lamiaceae.
ob- inversely; usually same shape as suffix but attached by the narrower end, for example obcordate, oblanceolate, obovate.
obconicof a fruit, hypanthium, pistil or calyx structure; an inverted cone shape, attached at apex.
obcordateof a leaf blade, broad and notched at the tip; heart shaped but attached at the pointed end.
obdiplostemonousstamens arranged in two whorls, and having twice as many as the petals, the outer whorl being opposite the petals. Compare: diplostemonous.
oblanceolatea 2-dimensional shape, lanceolate but broadest in the upper third.
obligateof parasites, unable to survive without the host; compare faculative.
obliqueslanting; of a leaf or stem, larger on one side of the midrib than the other, in other words asymmetrical.
obloidhaving a three dimensional oblong shape, e.g. a fruit.
oblonglength a few times greater than width, with sides almost parallel and ends rounded.
obovateof a leaf, a 2-dimensional shape of which the length is about 1.5 times the width, and widest above the centre.
obsoletenot evident, or at most rudimentary or
vestigial.
obtuseblunt or rounded; converging edges making an angle of more than 90°; compare acute. See Leaf shape.
ocrea (ochrea)a sheath, formed from two stipules, encircling the node in
Polygonaceae.
odd-pinnate(imparipinnate) having an odd number of leaflets in a compound leaf.
oft.often. Compare usu. and s.t.
-oideaeThe suffix added to the stem of a generic name to form the name of a subfamily: for instance,
Fumaria →
Fumarioideae.
olimformerly, e.g., "olim B", formerly in the Berlin herbarium (
Herbarium Berolinense).
ontogenythe sequence of developmental stages through which an organism passes.
opera utique oppressa (plural), and opus utique oppressum (singular)listed after the botanical name of a plant, or the name of a publication, this indicates that a publication is listed in the
International Code of Nomenclature for algae, fungi, and plants as a suppressed work. Botanical names of the specified rank in the publication are considered not validly published (article 34).
operculum (calyptra)a lid or cover that becomes detached at maturity, e.g. in
Eucalyptus, a cap covering the bud and formed by the fusion or cohesion of perianth parts.
opposite(as adjective) leaves or flowers borne at the same level but on opposite sides of the axis; or when something occurs on the same radius as something else, for example anthers opposite sepals; compare alternate.
orbicularflat and more or less circular.
ordera group of one or more families sharing common features, ancestry, or both.
ortetthe original single parent plant from which a clone ultimately derives.
orthotropouswhen an ovule is erect, with the micropyle directed away from the placenta; atropous; cf. amphitropous, anatropous, campylotropous.
ovalsee elliptical.
ovarythe basal portion of a carpel or group of fused carpels, enclosing the ovule(s).
ovateshaped like a section through the long-axis of an egg and attached by the wider end.
ovoidegg-shaped, with wider portion at base; 3-dimensional object, ovate in all sections through long-axis.
ovuleloosely, the seed before fertilization; a structure in a seed plant within which one or more megaspores are formed (after fertilization it develops into a seed).
pachycaulwith a disproportionately thick trunk
pachycladouswith disproportionately thick stems
palea(plural paleae)
1. the upper of two bracts enclosing a grass flower, major contributors to chaff in harvested grain.
2. Chaffy scales on the receptacles of many Asteraceae.3. Chaffy scales on the
stipe of many ferns.
paleatebearing paleae or chaffy scales, as in description of the receptacle of a capitulum of a plant in the Asteraceae.
paleaceousChaff-like in texture.
palmate1. leaf with veins radiating out from a central point (usually at the top of a petiole), resembling spread out fingers pointing away from the palm.2. A compound palmate leaf has leaflets that radiate from a central point (usually at the top of a petiole).
palmatifiddeeply divided into several lobes arising from more or less the same level.
palmatisectintermediate between palmate and palmatifid, i.e. the segments are not fully separated at the base; often more or less digitate.
panicle(adjective paniculate) a compound
raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these.
papilionatebutterfly-like; with a corolla like that of a pea.
papilla(plural papillae, adjective papillose, papillate) a small, elongated protuberance on the surface of an organ, usually an extension of one epidermal cell.
pappusin daisy florets, a tuft or ring of hairs or scales borne above the ovary and outside the corolla (representing the reduced calyx); a tuft of hairs on a fruit.
paraperigoniumAlso
paraperigone. Anomalous secondary outgrowth of the
perianthal meristem with ramifying vasculature. See also
perigonium,
perianth and
coronaparasitean organism living on or in a different organism, from which it derives nourishment; compare saprophyte, epiphyte.
parenchymaa versatile
ground tissue composed of living primary cells that performs a wide variety of structural and biochemical functions in plants.
parietalattached to the marginal walls of a structure, for example ovules attached to placentas on the wall of the ovary. See Placentation.
paripinnatehaving an even number of leaflets (or pinnae), that is terminated by a pair of pinnae as opposed to a single pinna; compare imparipinnate.
parthenocarpythe development or production of fruit without fertilization. compare
stenospermocarpy.
patentSpreading, erect, standing at 90
o to the axis. See also erecto-patent, patulous.
patulouspatent.
pauciflorhaving few flowers per inflorescence. See also pluriflor and uniflor.
pectinatepinnately divided with narrow segments closely set like the teeth of a comb.
pedatewith a terminal lobe or leaflet, and on either side of it an axis curving outwards and backwards, bearing lobe or leaflets on the outer side of the curve.
pedicel(adjective pedicellate) the stalk of a flower. May be applied to the stalk of a capitulum in Asteraceae
peduncle(adjective pedunculate) the stalk of an inflorescence.
peltateshield-like; with stalk attached to the lower surface and not to the margin.
pellucidtransmitting light; for example, said of tiny gland dots in the leaves of e.g.
Myrtaceae and
Rutaceae that are visible when held in front of a light.
penduloushanging, for example an ovule attached to a placenta on the top of the ovary; compare suspended.
penicillatetufted like an artist's brush; with long hairs towards one end.
penninervation (penninerved)with pinnately arranged veins.
pentamerousin five parts, particularly with respect to flowers, five parts in each whorl. See also trimerous and tetramerous.
pepotype of berry formed from an inferior ovary and containing many seeds, usually large with a tough outer skin, for instance,
pumpkin,
cucumber.
perennatingof an organ that survives vegetatively from season to season. A period of reduced activity between seasons is usual.
perenniala plant whose life span extends over several years.
perfectof a flower, when bisexual.
perfoliatewith its base wrapped around the stem (so that the stem appears to pass through it), e.g. of leaves and bracts.
perforatewith many holes. Used to describe the texture of pollen exine, and also to indicate that tracheary elements have a perforation plate. See also fenestrate.
perforation platein a tracheary element, part of the cell wall that is perforated; present in
vessel members but not in tracheids. Should not be confused with a pit.
perianththe collective terms for the calyx and corolla of a flower (generally used when the two are similar). Abbreviation: P. For instance P 3+3 indicates the calyx and corolla each have 3 elements, or 3 sepals + 3 petals
pericarpthe wall of a fruit, developed from the ovary wall.
periclinalCurved along parallel to a surface, cf. anticlinal.
perigoniumin flowering plants see perianth2. in mosses, the leaves surrounding the antheridia, also called a spash-cup, e.g. in
Polytrichum juniperinum.
perigyniuma sac around the pistillate flower of sedges
perigynousborne around the ovary, i.e. of perianth segments and stamens arising from a cup-like or tubular extension of receptacle (free from the ovary but extending above its base); cf. epigynous, hypogynous.
persistentremaining attached to the plant beyond the usual time of falling, for instance sepals not falling after flowering, flower parts remaining through maturity of fruit; compare deciduous, caducous.
perule (lat. perula, perulae)(adjective: perulate)
1. the scales covering a leaf or flower bud, or a reduced scale like leaf surrounding the bud. Buds lacking perulae are referred to as 'naked'2. in Camellias the final bracts and sepals become indistinguishable and are called perules.3. a kind of sac formed by the adherent bases of the two lateral sepals in certain orchids.
petalin a flower, one of the segments or divisions of the inner whorl of non-fertile parts surrounding the fertile organs, usually soft and conspicuously coloured; compare sepal.
petaloidlike a petal; soft in texture and coloured conspicuously.
petiolatea leaf with a petiole. Compare sessile.
petiolethe stalk of a leaf.
petiolulethe stalk of a leaflet.
petricolousRock-dwelling; living on or among rocks.
phaneranthousshowy, as in showy flowers that advertise to
pollinators, as opposed to aphananthous (unshowy)
phanerogamgymnosperms and angiosperms; plants producing stamens and gynoecia; literally plants with conspicuous sexual reproductive organs; cf. cryptogams.
phenologythe study of the timing of seasonal biological phenomena, such as flowering, leaf emergence, fruit ripening and leaf fall.
phloema specialised conducting tissue in vascular plants that transports
sucrose from the leaves to other plant organs.
photobiontIn a lichen, the component that does the photosynthesis, the
green algae (Chlorophyta) or blue-green algae (Cyanobacteria). (compare to mycobiont, the fungal component.) Also called the
phycobiont.
photosynthesisthe process by which sugars are made from
carbon dioxide and water in cells containing chloroplasts.
phycobiontIn a lichen, a synonym for photobiont
phyllidA leaf-like extension of the stem in Bryophytes
phyllode(adjective phyllodineous) a leaf with the blade much reduced or absent, and in which the petiole and or rachis perform the functions of the whole leaf; e.g. many acacias; cf. cladode.
phyllopodium(in ferns) a short outgrowth of the stem on which the frond is borne and that remains attached to the rhizome after the frond has been shed.
phyllospherethe above-ground surface of plants as a habitat for epiphytic microorganisms.
phytomelanalso
phytomelanin. A black, inert, organic material that forms a crust-like covering of some seeds, commonly found in
Asparagales, Asteraceae, etc. Adjective=
phytomelanouspilosecovered with soft, weak, thin and clearly separated hairs, which are usually defined as long and sometimes ascending.
pinna(plural pinnae) a primary segment of a compound leaf.
pinnatea compound leaf with leaflets arranged on each side of a common petiole or axis; also applied to how the lateral veins are arranged in relation to the main vein.
pinnatifidpinnately lobed.
pinnatisectpinnately divided almost to midrib but segments still confluent.
pinnuleultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf.
pistil1. a single carpel when the carpels are free.2. a group of carpels when the carpels are united by the fusion of their walls.
pistillate flowera flower containing pistils but no stamens
pitin tracheary elements, a section of the cell wall where the secondary wall is missing, and the primary wall is present. Pits generally occur in pairs and link two cells.
piththe central region of a stem, inside the vascular cylinder; the spongy parenchymatous central tissue in some stems and roots.
placentathe tissue within an ovary to which the ovules are attached.
placentationthe arrangement of ovules inside ovary; for example axile, free-central, parietal, marginal, basal, or apical.
placodioidThe form of a lichen thalus which radiates outward with the ends of the radiating arms peeling up from the substrate, but which lack a cortex on the underside (unlike foliose lichens).
Plant Breeders Rights (PBR)these rights, governed by Plant Breeder's Rights Acts give the plant breeder legal protection over the propagation of a cultivar, and the exclusive rights to produce and to sell it, including the right to license others to produce and sell plants and reproductive material of a registered, deliberately bred variety. Cf. UPOV.
Plant Variety Rights (PVR)governed by the Plant Variety Rights the registration of new varieties is now governed by Plant Breeders Rights.
Plastochronthe time between successive leaf initiation events.
plicatepleated; folded back and forth longitudinally like a fan, such as the leaves of many palm species. The concept often appears in specific names in forms such as
Aloe plicatilis and
Acacia plicata. Commonly such names are not correctly appropriate, but are applied to distichous structures rather than plicate.
-plinerved(of leaves) a suffix indicating that the main nerves are lateral and arise from a point distinctly above the base of the leaf. Combined with a numerical prefix to form words like 3-plinerved, 5-plinerved, and so on. Such leaves are especially characteristic of the family Melastomataceae.
plumoselike a feather; with fine hairs branching from a main axis.
plumulethe part of an embryo that gives rise to the shoot system of a plant; cf.
radicle.
pluriflorhaving many flowers per inflorescence. See also pauciflor and uniflor.
pluriovulatehaving many ovules as in placentae, carpels or ovaries.
pneumatophorea vertical, aerial (at low tide) appendage to the roots of some plants, through which gases are exchanged; e.g. on mangroves.
pod1. a legume, the fruit of a leguminous plant, a dry fruit of a single carpel, splitting along two sutures.2. siliqua and silicula, the fruit of
Brassicaceae, a dry fruit composed of two carpels separated by a partition.
pollenpowdery mass shed from anthers (of angiosperms) or microsporangia (of gymnosperms); the microspores of seed plants; pollen-grains.
pollen-masspollen-grains cohering by a waxy texture or fine threads into a single body;
pollinium; e.g. in orchids.
pollen transmitting tissuethe tissue in the style of a flower through which the
pollen tubes grow.
pollinationthe transfer of pollen from the male organ (anther) to the receptive region of a female organ (stigma).
polliniumsee pollen-mass.
polygamodioecioushaving bisexual and male flowers on some plants and bisexual and female flowers on others; cf. androdioecious, andromonoecious, dioecious, monoecious, polygamomonoecious, polygamous.
polygamomonoecioushaving male, female and bisexual flowers on the same plant; cf. androdioecious, andromonoecious, polygamodioecious, polygamous.
polygamoushaving bisexual and unisexual flowers on the same plant.
polymorphicof several different kinds (in respect to shape and/or size), hence polymorphism. See also
monomorphic (a single type) and
dimorphic (two types)
polyploidwith more than two of the basic sets of chromosomes in the nucleus; any sporophyte with cells containing three or more complete sets of chromosomes. Various combinations of words or numbers with '-ploid' indicate the number of haploid sets of chromosomes; e.g. triploid = 3 sets, tetraploid = 4 sets, pentaploid = 5 sets, hexaploid = 6 sets, and so on.
polystemonoushaving numerous stamens; the number of stamens being at least twice the number of sepals or petals, but not strictly three or four times that number.
pomea fruit that has developed partly from the ovary wall but mostly from the hypanthium, e.g.,
apple.
population1. all individuals of one or more species within a prescribed area.2. a group of organisms of one species, occupying a defined area and usually isolated to some degree from other similar groups.3. in statistics, the whole group of items or individuals under investigation.
poricidalopening by pores, like the capsule of a poppy, or like the anthers in several families of plants. compare: longicidal
posteriorpositioned behind, towards the rear, proximal; compare anterior, distal.
prickle(adjective: prickly) hard, pointed outgrowth from the surface of a plant (involving several layers of cells but not containing a vein); sharp outgrowth from the bark, detachable without tearing wood; cf.
thorn.
primary speciesIn lichens, a species reproducing mainly by sexual reproduction, not vegetative reproduction.
primary vein(venation) the single vein or array of veins that are conspicuously larger than any others in the leaf. In pinnate venation, the single primary vein is in the middle of the leaf. In palmate venation, several such veins radiate from a point at or near the base of the leaf.
propaguleIn lichens, a part of the thallus that has both fungal and algal parts and can break off for vegetative reproduction, e.g., an isidium, phyllidium, phyllocladium, or soredium).
prophylla leaf formed at the base of a shoot, usually smaller than those formed later.
pro parte(Latin) in part; in nomenclature, to denote that the preceding taxon includes more than one currently recognized entity, and that only one of those entities is being considered.
procumbentspreading along the ground but not rooting at the nodes: not as close to ground as prostrate.
propagulesa structure capable of producing a new plant; includes seeds, spores, bulbils, etc.
prostratelying flat on the ground.
protandrousmale sex organs maturing before the female ones, e.g. a flower shedding pollen before the stigma is receptive; cf. protogynous.
proteranthousnew leaves appear before flowers. See also
hysteranthous and
synanthousprothallusa #gametophyte plant, usually flattened and delicate; e.g. in ferns and fern allies.
protogynousfemale sex organs maturing before the male ones, e.g. a flower shedding pollen after the stigma has ceased to be receptive; cf. protandrous.
proximalnear the point of origin or attachment, cf. distal.
pruinosecovered with a powdery, waxy material; with a bloom.
pseudanthiuma particular form of inflorescence occurring in the Asteraceae and
Euphorbiaceae, in which multiple flowers are grouped together to form a flower-like structure, commonly called a head or capitulum.
pseudofalse; not genuine; e.g. pseudo-bulb = a thickened, bulb-like internode in orchids, or a corm.
pseudostipulean enlarged, persistent axillary bud scale that resembles a
stipule; common in
Bignoniaceae.
pseudoverticillatehaving the appearance of being whorled (verticillate), without actually being so.
puberulous (puberulent)covered with minute soft erect hairs.
pubescentdowny; covered with short, soft, erect hairs.
pulverulenthaving powdery or crumbly particles as if pulverized.
pulvinatewith a
pulvinuspulvinusa swelling at either end of a petiole of a leaf or petiolule of a leaflet, e.g. in Fabaceae, that permits leaf movement.
punctatemarked with dots.
punctiformdot-like
pungenthaving a sharp hard point.
pustuleA blister-like swelling.
pustulateHaving pustules.
pyramidalof a plant's form, tetrahedral, pyramid-shaped.
pyrenethe stone of a drupe, consisting of the seed surrounded by the hardened endocarp.
pyriformpear-shaped; a term for solid shapes that are broadest in the upper third and abruptly narrowed near the base.
quadratemore or less
square.
raceme(adjective racemose) an indeterminate inflorescence in which the main axis produces a series of flowers on lateral stalks, the oldest at the base and the youngest at the top; cf. spike.
rachilla (rhachilla)the axis of a grass spikelet, above the glumes.
rachis(plural rachises; rachides) the axis of an inflorescence or a pinnate leaf; for example ferns; secondary rachis is the axis of a pinna in a bipinnate leaf distal to and including the lowermost pedicel attachment.
radialwith structures radiating from a central point as
spokes on a wheel, for example, the lateral spines of a cactus.
radiateof daisies, of a capitulum, with ray florets surrounding disc florets.
radicalspringing from the root; clustered at base of stem.
radiclethe part of an embryo giving rise to the root system of a plant; cf. plumule.
rainforesta moist temperate or tropical forest dominated by broad-leaved trees that form a continuous canopy.
rametan individual member of a clone.
1. zygomorphic (ligulate) flowers in a radiate flowerhead, that is, ray-florets/flowers, for example Asteraceae.2. each of the branches of an
umbel.
receptaclethe axis of a flower, in other words, floral axis; torus; for example in Asteraceae, the floral base or receptacle is the expanded tip of the peduncle on which the flowers are inserted.
recurvedbent or curved backwards or downwards.
reduplicatefolded outwards, or with the two abaxial surfaces together.
reflexedbent sharply back or down.
registered namea cultivar name accepted by the relevant
International Cultivar Registration Authority.
registration1. the act of recording a new cultivar name with an
International Cultivar Registration Authority.2. recording a new cultivar name with a statutory authority like the Plant Breeder’s Rights Office.3. recording a
trademark with a trade marks office.
regularsee actinomorphic.
reniformkidney-shaped.
resupinate1. In botany, describing leaves or flowers that are in an inverted position because the petiole or pedicel, respectively, is twisted 180 degrees. compare: #hyper-resupinate2. In lichenology, referring to either having or being a fruiting body that lies flat on the substrate, with the hymenium either over the whole surface or at the periphery.
reticulateforming a network (or reticulum), e.g. veins that join one another at more than one point.
retrorsebent backwards or downwards; cf. antrorse.
retusewith a blunt (obtuse) and slightly notched apex.
revisionan account of a particular plant group, like an abbreviated or simplified monograph. Sometimes confined to the plants of a particular region. Similar to a monograph in clearly distinguishing the taxa and providing a means for their identification; compare monograph.
revoluterolled under (downwards or backwards), for example when the edges of leaves are rolled under towards the midrib; compare involute.
rhachissee rachis.
rhizineThe "root" or "trunk" projection of a foliose lichen that attaches the lichen to the substrate (what the lichen is growing on)
rhizodermisthe root epidermis, the outermost primary cell layer of the root
rhizomea perennial underground stem usually growing horizontally. See also
stolon. Abbreviation: rhiz.
rhizospherethe below-ground surface of plants and adjacent soil as a habitat for microorganisms.
rhombiclike a
rhombus: an oblique figure with four equal sides; compare trapeziform, trullate.
rhomboida four-sided figure with opposite sides parallel but with adjacent sides an unequal length (like an oblique rectangle); see also rhombic.
rhomboidala shape, for instance of a leaf, that is roughly diamond-shaped with length equal to width.
rimosewith many cracks, as in the surface of a
crustose areolate lichen.
roota unit of a plant's axial system which is usually underground, does not bear leaves, tends to grow downwards, and is typically derived from the radicle of the embryo.
root hairsoutgrowths of the outermost layer of cells just behind the root tips, functioning as water-absorbing organs.
root microbiomethe dynamic community of microorganisms associated with plant roots.
rootstock1. the part of a budded or grafted plant which supplies the root system, also simply called a
stock.2. plants selected to produce a root system with some specific attribute, e.g. a
virus-free rootstock.
rosettewhen parts are not whorled or opposite but appear so, due to the contractions of internodes, e.g. the petals in a double rose or a basal cluster of leaves (usually close to the ground) in some plants.
rostratewith a beak.
rotatecircular and flattened; for example a corolla with a very short tube and spreading lobes (for instance some
Solanaceae).
ruderala plant that colonises or occupies disturbed waste ground. See also weed.
rudimentarypoorly developed and not functional; compare vestigial.
rugosewrinkled.
rugulosefinely wrinkled.
ruminate(usually applied to endosperm). irregularly grooved or ridged; appearing chewed. (a common type of endosperm in
Myristicaceae).
runcinatesharply pinnatifid or cleft, the segments directed downward.
runnerssee stolon.
rupicolousrupestral, saxicolous, growing on or among rocks. (compare epilithic, lithophytic)
rusha plant belonging to the family
Juncaceae or, more loosely, applied to various monocotyledons.
saccatepouched or shaped like a sack.
sagittateshaped like the head of an arrow; narrow and pointed but gradually enlarged at base into two straight lobes directed downwards; may refer only to the base of a leaf with such lobes; cf. hastate.
salverformtrumpet-shaped; with a long, slender tube and a flat, abruptly expanded limb.
samaraa dry, indehiscent fruit with its wall expanded into a wing, e.g. in the genus
Acer.
samphirea common name given to various edible coastal plants, such as
Salicornia spp. (
Amaranthaceae),
Crithmum maritimum (
Apiaceae) and
Limbarda crithmoides (Asteraceae).
saprophyte(adjective saprophytic) an organism deriving its nourishment from decaying organic matter and usually lacking chlorophyll; compare parasite, epiphyte.
sarmentosehaving long, slender, prostrate
stolons (runners).
saxicolousgrowing on stone, like some lichens.
scabrid (scabrous) rough to the touch with short hard emergences or hairs.
scalariformladderlike in structure or appearance.
scale1. a reduced or rudimentary leaf, for example around a dormant bud.2. a flattened epidermal outgrowth, such as those commonly found on the leaves and rhizomes of ferns.
scandentclimbing, by whatever means. See also: scandent in Wiktionary.
scape(adjective scapose) a stem-like flowering stalk of a plant with radical leaves.
scaposehaving the floral axis more or less erect with a few leaves or devoid of leaves; consisting of a scape.
scariousdry and membranous.
schizocarpa dry fruit formed from more than one carpel but breaking apart into individual carpels (mericarps) when ripe.
scionthe aerial part of a graft combination, induced by various means to unite with a compatible understock/rootstock.
sclereida cell with a thick, often lignified, cell wall that is shorter than a fiber cell and dies soon after the thickening of its cell wall.
sclerenchymaa strengthening or support tissue composed of sclereids or of a mixture of sclereids and fibers.
sclerophyll(adjective sclerophyllous) a plant with hard, stiff leaves; leaves stiffened with thick-walled cells.
scorpioidof a cymose inflorescence, when it branches alternately on one side and then the other; cf. helicoid.
scrobiculatewith very small pits.
scrublanddense vegetation dominated by shrubs.
scurfminute loose, membranous scales on the surface of some plant parts e.g. leaves.
secondary metabolitechemicals produced by a plant that do not have a role in "primary" functions such as growth, development, photosynthesis, reproduction, etc.
secondary speciesIn lichens, a "species" taxon of lichen reproducing only by vegetative means, whose components reproduce mainly by sexual means – cf. primary species.
secretory tissuethe tissues concerned with the secretion of gums, resins, oils and other substances in plants.
section (sectio)the category of supplementary taxa intermediate in rank between
subgenus and series. It is a singular noun always written with a capital initial letter, in combination with the generic name.
secundwith all the parts grouped on one side or turned to one side (applied especially to inflorescences).
sedgea plant belonging to the family
Cyperaceae.
seeda ripened ovule, consisting of a protective coat enclosing an embryo and food reserves; a propagating organ formed in the sexual reproductive cycle of gymnosperms and angiosperms (together, the seed plants).
segmentpart or subdivision of an organ, for example a petal is a segment of the corolla. A term sometimes used when the sepals and petals are indistinguishable.
self-pollinationalso called selfing, the acceptance by stigmas of pollen from the same flower or from flowers on the same plant, which means they are self-compatible.
semaphylla structure such as a bract or a sepal (if the remainder of the perianth is inconspicuous) which has become modified to attract
pollinators. Plural: semaphylls
semelparityWhen a plant flowers once then dies.
semiterete(or semi-
terete), rounded on one side, but flat on the other. See also terete
sensitivea descriptive term for stigmas that, in response to touch, close the two lobes of the stigma together, ending the receptivity of the stigma, at least for the time that the lobes are closed together.
Mimulus is perhaps the best-known example.
sensuin the sense of.
sensu auct.of a plant group or name, as cited by a named authority.
sensu amploof a plant group or name, in a generous or ample sense.
sensu latoof a plant group, in a broad sense.
sensu strictissimoof a plant group, in the narrowest sense.
sensu strictoof a plant group, in a narrow sense.
sepalin a flower, one of the segments or divisions of the outer whorl of non-fertile parts surrounding the fertile organs, usually green; compare petal.
septicidalof a fruit, when it dehisces along the partitions between loculi; cf. loculicidal.
septum(plural septa) a partition, for example the membranous wall separating the two valves of the pod of
Brassicaceae.
seriatearranged in rows.
sericeoussilky with dense appressed hairs.
seriesthe category of supplementary taxa intermediate in rank between section and species. It is a plural adjective; for instance
Primula subgenus
Primula sect.
Primula series
Acaules.
serratetoothed with asymmetrical teeth pointing forward; like the cutting edge of a saw.
serrulatefinely serrate.
sessileattached without a stalk, e.g. of a leaf without a petiole or a stigma, when the style is absent.
seta(adjectives setose, setaceous) a bristle or stiff hair (in Bryophytes, the stalk of the sporophyte); a terminal seta is an appendage to the tip of an organ, e.g. the primary rachis of a bipinnate leaf in Acacia.
sheatha tubular or rolled part of an organ, e.g. the lower part of the leaf in most grasses.
shootusually the aerial part of a plant; a stem including its dependent parts, leaves flowers etc.
shruba woody perennial plant without a single main trunk, branching freely, and smaller than a tree.
sigmoidshaped like the letter 'S'.
siliculaa stout siliqua (not more than twice as long as wide).
siliquaa dry, dehiscent fruit (more than twice as long as wide) formed from a superior ovary of two carpels, with two parietal placentas and divided into two loculi by a 'false' septum.
silkydensely covered with fine soft straight appressed hairs, with a lustrous sheen and satiny to the touch.
silviculturethe science of
forestry and the cultivation of
woodlands for commercial purposes and wildlife conservation.
simpleundivided, for instance a leaf not divided into leaflets (note, however, that a simple leaf may be entire, toothed or lobed) or an unbranched hair or inflorescence.
sinuatewith deep, wave-like depressions along the margins, but more or less flat; compare undulate.
sinusa notch or depression between two lobes or teeth in the margin of an organ.
solitarysingle, of flowers that grow one plant per year, one in each axil, or widely separated on the plant; not grouped in an inflorescence.
soraliaIn a lichen, the structure that bears soredium for non sexual reproduction.
sorediaplural of soredium
sorediumIn a lichen, a small groups of algal cells surrounded by fungal filaments that form in soralia, which break off and grow new lichens without sexual reproduction after being dispersed by wind. Compare to an isidium, which breaks off and is dispersed by mechanical means.
sp.abbreviation of species (singular), often used when the genus is known but the species has not been determined, as in
Brassica sp.
spp.abbreviation of species (plural). See sp.
spadixa spicate (spike-like) inflorescence with a stout, often succulent axis.
spathe(adj. spathaceous), a large bract ensheathing an inflorescence. Traditionally any broad flat blade.
spathulate (spatulate)spoon-shaped; broad at the tip with a narrowed projection extending to the base.
speciesa group, or populations of individuals, sharing common features and/or ancestry, generally the smallest group that can be readily and consistently recognized; often, a group of individuals capable of interbreeding and producing fertile offspring. The basic unit of classification, the category of taxa of the lowest principal rank in the nomenclatural hierarchy.
specific epithetfollows the name of the genus, and is the second word of a botanical binomial. The generic name and specific epithet together constitute the name of a species; i.e. the specific epithet is not the species name.
spica (adjective spicate) a spike.
spike(adjective spicate) an unbranched, indeterminate inflorescence in which the flowers are without stalks; cf. raceme.
spikeleta unit of the inflorescence especially in grasses, sedges and some other monocotyledons, consisting of one to many flowers and associated bracts (glumes).
spine(adjective spinose) a stiff, sharp structure, formed by the modification of a plant organ that contains vascular tissue; e.g. a lateral branch or a stipule; includes thorns.
spinescentending in a spine; modified to form a spine.
spiralof arrangement, when plant parts are arranged in a succession of curves like the thread of a screw, or coiled in a cylindrical or conical manner.
splash-cup (sporangia)A cup-like structure in cryptograms for spore dispersal whereby energy of raindrops hitting into the cup splash back out carrying the spore.
sporangium (sporangia)a structure in which spores are formed.
sporangiophorean organ bearing sporangia, e.g. in the cones of
Equisetum.
sporea haploid propagule, produced by
meiosis in diploid cells of a sporophyte that can germinate to produce a multicellular gametophyte.
sporocarpa fruiting body containing spores.
sporophylla modified leaf that bears a sporangium or sporangia, in pteridophytes.
sporophytethe haploid multicellular phase in the alternation of generations of plants and algae that produces the spores; cf. gametophyte.
sporta naturally occurring variant of a species, not usually present in a population or group of plants; a plant that has spontaneously mutated so that it differs from its parent plant.
spreadingextending horizontally, for example branches; standing out at right angles to axis, for example leaves or hairs.
spur1. a short shoot.2. a conical or tubular outgrowth from the base of a perianth segment, often containing nectar.
squamule(plural squamules, squamulae) small scales; In lichens, squamules are overlapping plate-like forms, sometimes overlapping so much as to become leaf-like, but which lack a lower cortex, unlike the leafy forms of foliose lichens – adjective: squamulose
squamuloseCovered with small scales (squamules). In lichens, being composed of squamules
squarrosewith tips of leaves, stems etc. radiating or projecting outwards as in the
moss Rhytidiadelphus squarrosus.
s.t.abbreviation for
sometimes, compare usu. and oft.
stalkthe supporting structure of an organ, usually narrower in diameter than the organ.
stamen(adjective staminate) male organ of a flower, consisting (usually) of a stalk (filament) and a pollen-bearing portion (anther).
staminate flowera flower with stamens but no pistil
staminodea sterile stamen, often rudimentary, sometimes petal-like.
standardthe large posterior petal of pea-flowers.
standard specimena representative specimen of a cultivar (or other taxon), one that demonstrates how the name of that taxon should be used.
stelethe primary vascular system (phloem,
xylem and ground tissue) of plant stems and roots.
stellatestar-shaped, for example a type of hair.
stemthe plant axis, either aerial or subterranean, which bears nodes, leaves, branches and flowers.
stem-claspingsee amplexicaul.
stenospermocarpythe development or production of fruit that is seedless or has minute seeds because of the abortion of seed development. compare parthenocarpy
sterileinfertile, for example a stamen that does not bear pollen, or a flower that does not bear seed.
stigmathe pollen-receptive surface of a carpel or group of fused carpels, usually sticky; usually a point or small head at the summit of the style.
stipein ferns, the stalk of a frond; generally a small stalk.
stipella(stipel; plural stipellae) one of two small secondary stipules at the base of leaflets in some species.
stipitatestalked; borne on a stipe; of an ovary, borne on a gynophore.
stipulatebearing stipules.
stipulesmall appendage at the bases of leaves in many dicotyledons.
stolonslender, prostrate or trailing stem, producing roots and sometimes erect shoots at its nodes. See also rhizome.
stocksee rootstock.
stoloniferoushaving stolons.
stoma (plural stomata) a pore; small hole in the surface of a leaf (or other aerial organ) allowing the exchange of gases between tissues and the atmosphere.
striatestriped with parallel, longitudinal lines or ridges.
strigosecovered with appressed, rigid, bristle-like, straight hairs; the appressed equivalent of hispid.
strobilus (plural strobili) a cone-like structure consisting of sporophylls (e.g. conifers and club mosses) or sporangiophores (e.g. in Equisetopsida) borne close together on an axis.
stylean elongated part of a carpel, or group of fused carpels, between the ovary and the stigma.
stylodiuman elongate stigma that resembles a style, a false style, e.g. commonly found in
Poaceae and Asteraceae.
stylulusthe elongated apex of a free carpel which functions like the style of a syncarpous ovary, allowing
pollen tubes from its stigma to enter the locule of only that carpel.
subcoriaceousslightly leathery or coriaceous.
subgenusthe category of supplementary taxa intermediate between genus and section. It is a singular noun, always has a capital initial letter and is used in combination with the generic name; e.g.
Primula subgenus
Primula.
subgloboseInflated, but less than spherical. See also
globose.
subshrubundershrub; small shrub which may have partially herbaceous stems, but generally a woody plant less than 1 m high.
subspeciesa grouping within a species, usually used for geographically isolated and morphologically distinct entities. Its taxonomic rank occurs between species and variety.
subtendto stand beneath or close to, as in a bract at the base of a flower.
subquadrangularnot quite square; see also quadrangular in wiktionary.
subulatenarrow and tapering gradually to a fine point.
succulentjuicy, fleshy; a plant with a fleshy habit.
suckera shoot of more or less subterranean origin; an erect shoot originating from a bud on a root or a rhizome, sometimes at some distance from the stem of the plant.
suffrutexsubshrub or undershrub.(plural suffrutices). See also
suffrutex for etymology etc.
sulcatefurrowed; grooved. May be single (monosulcate), two (bisulcate) or many (polysulcate)
superficialon the surface.
superiorof an ovary, borne above the level of attachment of the other floral parts, or above the base of a hypanthium; compare inferior, half-inferior.
suspendedof an ovule, when attached slightly below the summit of the ovary; compare pendulous.
suturea junction or seam of union. (see fissure, commissure)
swardextensive, more or less even cover of a surface, for example a lawn grass; compare tussock.
sympatricwith more or less similar or overlapping ranges of distribution.
sympodiala mode of growth in which the main axis is repeatedly terminated, and replaced with a lateral branch. Examples occur in the family
Combretaceae, including the genera
Terminalia and
Combretumsyconiuma hollow
infructescence containing multiple fruit, such as that of a fig.
syn- (sym-) with, together.
symmetricalcapable of being divided into at least two equal, mirror-image halves (e.g. zygomorphic) or to have rotational symmetry (e.g. regular, actinomorphic). Contrast with irregular, asymmetrical.
sympetalouswith united (connate or fused) petals.
synangiuma fused aggregate of sporangia, e.g. in the trilocular (=with three chambers) sporangia of the whisk fern
Psilotum.
synanthousnew leaves and flowers appear and die back at the same time. See also
hysteranthous and
proteranthoussynaptospermyThe dispersal of diaspores as units, where each bears more than one seed, for example where each diaspore comprises an entire inflorescence, as in
Brunsvigia or multi-seeded fruit as in
Tribulus zeyheri.
Ephemeral synaptospermy is the term for when the diaspores split into units containing fewer or single seeds each, as in most
tumbleweeds.
True synaptospermy is when the diaspore generally remains entire until germination, as commonly happens in species of
Grielum.
syncarpousof a gynoecium, made up of united carpels.
synonymoutdated name or 'alternative' name for the same taxon.
synoeciousSynonym of bisexual.
taprootthe main, descending root of a plant with a single dominant root axis.
tartareoushaving a surface that is course, thick, rough, and crumbling.
taxon (plural taxa) a group or category in a system of classification, derived from the Greek prefixes taxo-, taxis- meaning arrangement.
taxonomythe study of the principles and practice of classification.
tegmenthe inner layer of the testa (seed coat). It develops from the inner integument of the ovule.
tendrila slender organ (modified e.g. from stem, leaf, leaflet or stipule) used by climbing plants to cling to an object.
tepalperianth segment, either sepal or petal; usually used when all perianth segments are similar in appearance; cf. petal.
teretecircular in cross-section; more or less cylindrical without grooves or ridges. Also
semiterete.
terminalsituated at the tip or apex.
ternatein groups of three; of leaves, arranged in whorls of three; of a single leaf, with the leaflets arranged in groups of three. See Leaf shape.
terrestrialgenerally denotes of or on the ground; of habitat, on land as opposed to in water (aquatic) or on rocks (lithophytic), or other plants (epiphytic), and so on.
testaseed coat.
tetrada group of four; usually means four pollen grains remaining fused together a maturity, e.g. in the Epacridaceae.
tetragonalsquare, with four corners, four-angled, e.g. the cross section of the stems of herbaceous
Lamiaceae.
tetramerousin four parts, particularly with respect to flowers, four parts in each whorl. See also trimerous and pentamerous.
tetraploidhaving four complete sets of chromosomes in each sporophyte cell.
tetrasporethe asexual spore of
red algae. It is so named because each sporangium produces just four spores. See Rhodophyceae.
thalamusobsolete. 1) see receptacle; 2) the inflorescence disk of Asteraceae; 3) as used by
Carl Linnaeus, the calyx
thallusThe "vegetative" part (part other than sexual fruitbodies) of a lichen that has both the fungus (mycobiont) and photobiont; plural
thallithecaone of the usually two synangia in which pollen is produced in flowering plants. It consists of two fused sporangia known as pollen sacs. The wall between the pollen sacs disintegrates before dehiscence, which is usually by a common slit.
thorna sharp, stiff point, usually a modified stem, that cannot be detached without tearing the subtending tissue; a spine; cf. prickle.
throatthe opening of a corolla or perianth.
thyrsea branched inflorescence in which the main axis is indeterminate (racemose) and the lateral branches determinate (cymose).
tomentum(adjective tomentose) a dense covering of short, matted hairs. Tomentose is often used as a general term for bearing an indumentum, but this is not a recommended use.
toothedwith a more or less regularly incised margin.
torussee receptacle.
transmitting tissuesee pollen transmitting tissue.
trapeziform1. like a trapezium (a four-sided figure with two parallel sides of unequal length)2. like a trapezoid (a four-sided figure, or
quadrilateral, with neither pair of sides equal); sometimes used erroneously as a synonym for rhombic.
treea woody plant, usually with a single distinct trunk and generally more than 2-3 m tall.
triada group of three.
triangularplanar and with 3 sides.
tribea taxonomic grouping, in rank between genus and family.
trichomein non-filamentous plants, any hair-like outgrowth from epidermis, e.g. a hair or bristle; sometimes restricted to unbranched epidermal outgrowths.
trifidsplit into three parts. See also bifid.
trifoliolate (or trifoliate) a compound leaf of three leaflets, for example a
clover leaf.
trigonoustriangular in cross-section and obtusely angled; cf. triquetrous.
trimerousin three parts, particularly with respect to flowers, three parts in each whorl. See also tetramerous and pentamerous.
trinervedhaving three nerves or veins.
triplinerved(of leaves) having three main nerves with the lateral nerves arising from the midnerve above the base of the leaf.
triquetrousmore or less triangular in cross-section, but acutely angled (with 3 distinct longitudinal ridges); cf. trigonous.
trivalvealso
trivalvar. Divided into three valves. See also
bivalvetrivial namethe second word in the two-part scientific name of an organism; cf. specific epithet.
trophophylla vegetative, nutrient-producing leaf or microphyll, whose primary function is photosynthesis. It is not specialized or modified for some other function. (compare: sporophyll).
trullateovate but angled; like a bricklayer's
trowel; inverse
kite-shaped; compare rhombic.
truncatecut off squarely; with an abruptly transverse end.
trunkthe upright large main stem of a tree.
trussa compact cluster of flowers or fruits arising from one centre; for instance, evident in many
rhododendrons.
tuberan underground storage organ formed by the swelling of an underground stem which produces buds and stores food, forming a seasonal perennating organ, for example
potato; compare tuberoid.
tuberclea small
wart-like outgrowth.
tuberculatecovered in tubercles; warty.
tuberoidan underground storage organ formed by the swelling of a root; occurs in many orchids.
tuberousresembling a tuber; producing tubers.
tubularwith the form of a tube or cylinder.
tufteddensely fasciculate at the tip.
tunicouter covering of some bulbs and
corms, hence
tunicate.
tunicateof bulbs, consisting of concentric coats.
turbinatetop-shaped.
turgidswollen with liquid; firm; compare flaccid.
tussocka dense tuft of vegetation, usually well separated from neighbouring tussocks, for example some grasses; compare sward.
two-rankedhaving leaves arranged in two rows in the same plane, on opposite sides of the branch; = distichous.
typean item (usually a herbarium specimen) to which the name of a taxon is permanently attached, i.e. a designated representative of a plant name. Important in determining the priority of names available for a particular taxon.
type genusin nomenclature, the genus from which the family is based.
typographythe presentation of printed matter, covering issues such as type styles (e.g. italic or roman type), underlining, emboldening and letter spacing.
umbel(adjective umbellate) a racemose inflorescence in which all the individual flower stalks arise in a cluster at the top of the peduncle and are of about equal length; in a simple umbel, each stalk is unbranched and bears only one flower; a cymose umbel looks similar to an umbel but its flowers open centrifugally.
umboa rounded elevation, such as in the middle of the top of an umbrella or mushroom; a central boss or protuberance, such as on the cone scale of a
pineumbonatehaving an umbo, with a conical or blunt projection arising from a flatter surface, as on the top of a mushroom, or in the scale of a pine cone.
unciformhook shaped.
uncinatewith a hook at the apex.
undershruba low shrub, often with flowering branches that die off in winter; cf. subshrub.
understoryplant life growing beneath the forest canopy.
undulatewavy and not flat; compare sinuate.
uniflorhaving a single flower (uniflory). Compare pauciflor (few) and pluriflor (many)
unilocularhaving one loculus or chamber, e.g., the ovary in the families
Proteaceae and Fabaceae.
uniserialArranged in a single row or series. Unbranched. Uniseriate.
uniseriateArranged in a single row or series. Unbranched. Uniserial.
unisexualof one sex; bearing only male or only female reproductive organs, dioecious, dioicous. See Sexual reproduction in plants.
unitegmic(of an ovule), covered by a single integument.
urceolateliterally means "shaped like an
urn" (or
pitcher), with a swollen middle and narrowing top. Examples of urceolate plant structures are the pitchers of many species of the
pitcher plant genera
Sarracenia and
Nepenthes. Etymology: Mid-18th century, From Latin urceolus "little pitcher", urceus "pitcher".
usu.abbreviation for
usually, compare s.t. and oft.
utriclea small bladder; a membranous bladder-like sac enclosing an ovary or fruit; in sedges a fruit in which the pericarp is larger than, and loosely encloses, the seed.
vallecular canala resin canal coinciding with a longitudinal groove in the seeds of Asteraceae. A longitudinal cavity in the cortex of the stems of
Equisetum, coinciding with a groove in the stem surface.
valvateof sepals and petals in bud, which meet edge to edge but do not overlap.
valvea portion of an organ that fragments or splits open, for example the teeth-like portions of a pericarp in a split (dehisced) capsule or pod when ripe.
varsee varietas.
varianta plant or group of plants showing some measure of difference from the characteristics associated with a particular taxon.
varietas (variety in common usage, abbreviated as var.)(Latin) in the Linnean hierarchy a rank below that of species, between the ranks of subspecies and form.
variegatedirregularly marked with blotches or patches of another colour.
vascularan adjective referring to the conducting tissues, the (xylem and phloem), in vascular plants.
vascular bundlea bundle of vascular tissue in the primary stems of vascular plants, consisting of specialised conducting cells for the transport of water (xylem) and assimilate (phloem).
vasculumContainer used by botanists for collecting field specimens.
veina strand of vascular tissue, e.g. in vascular plant leaves; nerve.
veinleta small vein; the ultimate (visible) division of a vein.
velamena spongy tissue covering the aerial roots of orchids and some other epiphytes.
velvetydensely covered with fine, short, soft, erect hairs.
venationthe arrangement of veins in a leaf.
ventralthe front; in particular, towards the axis (adaxial) in a lateral organ or towards the substrate in a prostrate plant; contrast dorsal, abaxial.
vernationthe arrangement of unexpanded leaves in a bud; the order of unfolding of leaves from a bud.
verruciformwart-like in form.
verrucosewith warts.
verruculoseminutely warty, minutely verrucose.
versatileof anthers, swinging freely about the point of attachment to the filament.
verticillatearranged in one or more whorls, i.e. several similar parts arranged at the same point of the axis. e.g. leaf arrangement. Hence pseudoverticillate, appearing whorled or verticillate but not so
verticillastera type of pseudo-verticillate inflorescence, typical of Lamiaceae, in which pseudo-whorls are formed from pairs of opposite cymes.
vesicularof hairs, bladder-like; vesciculous, bearing such hairs.
vessela capillary tube formed from a series of open-ended cells in the water-conducting tissue of a plant.
vestigialreduced in form and function from the normal or ancestral condition.
villousAbounding in or covered with long, soft, straight hairs; shaggy with soft hairs.
vine1.
Vitis.2. Scandent plants climbing by means of trailing or twining stem or runner.3. Such a stem or runner
virgateWand-shaped, twiggy, especially referring to erect, straight stems. Diminutive: virgulate. In
mycology, referring to a
pileus with radiating ribs or lines.
Viridiplantaeliterally "green plants". A clade of autotrophic organisms that includes green algae,
Charophyta and land plants, that have cellulose in their cell walls, chloroplasts derived from primary endosymbiosis with Cyanobacteria that contain chlorophylls a and b and lack phycobilins.
viscidsticky; coated with a thick, syrupy secretion.
viviparous1. seeds or fruits which germinate before being shed from the parent plant.2. the development of plantlets on non-floral organs e.g. leaves.
wartya surface covered with small round protuberances, especially in fruit, leaves, twigs and bark, see tuberculate.
watershootan erect strong-growing or epicormic shoot developing from near the base of a shrub or tree, but distinct from a sucker.
weed1. a weed is loosely defined as a plant growing where it is not wanted; commonly associated with disrupted habitats. See also ruderal2. agricultural weed: an unwanted plant which grows among agricultural crops.3. environmental weed: naturalised, exotic or ecologically 'out-of-balance' indigenous species outside the agricultural or garden context which, as a result of invasion, adversely affects the survival or regeneration of indigenous species in natural or partly natural vegetation communities (Carr, G.W., in Foreman & Walsh, 1993).
wildoriginating from a known wild habitat (
wilderness). See Wildlife.
whorla ring of organs borne at the same level on an axis, for example leaves, bracts or floral parts.
wing1. a membranous expansion of a fruit or seed which aids in dispersal, for instance on pine seeds.2. a thin flange of tissue extending beyond the normal outline of a structure, e.g. on the column of some orchids, on stems, on petioles.3. one of the two lateral petals of a flower of subfamily
Faboideae of family Fabaceae, located between the adaxial standard (banner) petal and the two abaxial keel petals.
woollyvery densely covered with long, more or less matted or intertwined hairs, resembling sheep's wool.
xeromorpha plant with structural features (e.g. hard or succulent leaves) or functional adaptations that prevent water loss by evaporation; usually associated with arid habitats, but not necessarily drought-tolerant; cf.
xerophyte.
xerophytea plant generally living in a dry habitat, typically showing xeromorphic or succulent adaptation; a plant able to tolerate long periods of drought; cf. xeromorph.
xylema specialised water-conducting tissue in vascular plants.
zonatehaving light and dark circular bands or rings.
zygomorphicbilaterally symmetrical; symmetrical about one vertical plane only; applies to flowers in which the perianth segments within each whorl vary in size and shape; compare actinomorphic, irregular.
zygotea fertilized cell, the product of fusion of two gametes.