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Ophioglossaceae

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Kingdom
  
Plantae

Scientific name
  
Ophioglossaceae

Rank
  
Family

Division
  
Pteridophyta

Higher classification
  
Leptosporangiate fern

Order
  
Ophioglossales

Ophioglossaceae Botrychium daucifolium Ophioglossaceae image 59178 at PhytoImages

Lower classifications
  
Botrychium, Ophioglossum, Sceptridium multifidum, Helminthostachys zeylanica, Mankyua

Ophioglossaceae, the adder's-tongue family, is a family of ferns (though some studies have instead suggested a closer relationship to angiosperms), currently thought to be most closely related to Psilotaceae, the two together comprising the class Ophioglossidae as the sibling group to the rest of the ferns. The Ophioglossaceae is one of two groups of ferns traditionally known as eusporangiate ferns.

Contents

Ophioglossaceae Ophioglossaceae Agardh Springer

Description

These ferns differ from the other ferns in several respects:

Ophioglossaceae httpsuploadwikimediaorgwikipediacommonsthu

  • they produce only a single leaf at a time
  • instead of the leptosporangia typical of most ferns they produce eusporangia, which are larger, contain more spores, and have thicker walls
  • their sporophylls are divided into two distinct parts, the sporophore which produces sporangia and has a greatly reduced and modified blade, and the trophophore, which is very similar to the trophophylls in size, color, shape, and so forth
  • their gametophytes are subterranean and rely on fungi for their energy (in other words, they are mycoheterotrophic), unlike the terrestrial, photosynthetic gametophytes found in most ferns.

    • Ophioglossaceae FileOphioglossaceae spp Moore51png Wikimedia Commons

    Members of Ophioglossaceae are usually terrestrial (excepting a few epiphytic species of Ophioglossum) and occur in both temperate and tropical areas. The leaves are usually fleshy, and in temperate areas will often turn brownish or reddish during colder months. In addition to having mycoheterotrophic gametophytes, there are a few members of Botrychium that are unique among ferns in having the sporophytes also mycoheterotrophic, producing only small, ephemeral sporophylls that do not photosynthesize.

    Ophioglossaceae Ophioglossaceae Wikipdia a enciclopdia livre

    Adder's tongue (Ophioglossum reticulatum), a member of this family, is notable for having as many as 1260 chromosomes. For comparison, humans have 46 chromosomes, consisting of 23 pairs.

    Classification

    Ophioglossaceae Ophioglossaceae Index

    In all modern classifications, from the Smith system of 2006 forward, Ophioglossaceae is the single family in order Ophioglossales. The Smith system of 2006 divides the family into four genera: Botrychium s.l. (including Sceptridium, Botrypus, and Japanobotrychium), Helminthostachys, Mankyua, and Ophioglossum s.l. (including Cheiroglossa and Ophioderma). Christenhusz et al., in 2011, recognized Cheiroglossa as a segregate of Ophioglossum. The Christenhusz and Chase system of 2014 included Cheiroglossa in Ophioglossum again. The PPG I system divides the family into four subfamilies:

    Ophioglossaceae PHOTOGRAPHS OF FERNS OF THE INTERIOR HIGHLANDS

  • Helminthostachyoideae, containing Helminthostachys
  • Mankyuoideae, containing Mankyua
  • Ophioglossoideae, containing Cheiroglossa, Ophioderma, Ophioglossum, and Rhizoglossum (equivalent to Ophioglossum s.l. in other systems)
  • Botrychioideae, containing Botrychium, the non-monophyletic genus Botrypus, Japanobotrychium, and Sceptridium (similar to the circumscription of Kato; equivalent to Botrychium s.l. in other systems)

    • References

    Ophioglossaceae Wikipedia
    (Text) CC BY-SA