Asimina

Names

The genus name Asimina was first described and named by Michel Adanson, a French naturalist of Scottish descent. The name is adapted from the Native American name assimin through the French colonial asiminier.

The common name pawpaw, also spelled paw paw, paw-paw, and papaw, probably derives from the Spanish papaya, perhaps because of the superficial similarity of their fruits.

Description

Pawpaws are shrubs or small trees to 2–12 m (6.6–39.4 ft) tall. The northern, cold-tolerant common pawpaw (Asimina triloba) is deciduous, while the southern species are often evergreen.

The leaves are alternate, obovate, entire, 20–35 cm (7.9–13.8 in) long and 10–15 cm (3.9–5.9 in) broad.

The flowers of pawpaws are produced singly or in clusters of up to eight together; they are large, 4–6 cm across, perfect, with six sepals and petals (three large outer petals, three smaller inner petals). The petal color varies from white to purple or red-brown.

The fruit of the common pawpaw is a large edible berry, 5–16 cm (2.0–6.3 in) long and 3–7 cm (1.2–2.8 in) broad, weighing from 20–500 g (0.71–17.64 oz), with numerous seeds; it is green when unripe, maturing to yellow or brown. It has a flavor somewhat similar to both banana and mango, varying significantly by cultivar, and has more protein than most fruits.

Species and their distributions

1. Asimina angustifolia Raf. 1840 not A. Gray 1886; Florida, Georgia, Alabama, South Carolina Not a valid species
2. Asimina incana (W. Bartram) Exell - woolly pawpaw. Florida and Georgia. (Annona incana W. Bartram)
3. Asimina longifolia Raf. - slimleaf pawpaw. Florida, Georgia, and Alabama.
4. Asimina obovata (Willd.) Nash - bigflower pawpaw. Florida (Annona obovata Willd.)
5. Asimina manasota DeLaney - manasota papaw native to two counties in Florida (Manatee + Sarasota); first described in 2010 Not a valid species
6. Asimina × nashii Kral. - Florida and Georgia.
7. Asimina obovata (Willd.) Nash - flag-pawpaw or bigflower pawpaw - Florida
8. Asimina parviflora (Michx.) Dunal - smallflower pawpaw. Southern states from Texas to Virginia.
9. Asimina pygmea (W. Bartram) Dunal - dwarf pawpaw. Florida and Georgia.
10. Asimina reticulata Shuttlw. ex Chapman - netted pawpaw. Florida and Georgia.
11. Asimina spatulata (Kral) D.B.Ward - slim leaf pawpaw. Florida and Alabama Not a valid species
12. Asimina tetramera Small - fourpetal pawpaw. Florida (endangered)
13. Asimina triloba (L.) Dunal - common pawpaw. Extreme southern Ontario, Canada, and the eastern United States from New York west to southeast Nebraska, and south to northern Florida and eastern Texas. (Annona triloba L.)

Ecology

The common pawpaw is native to shady, rich bottom lands, where it often forms a dense undergrowth in the forest, often appearing as a patch or thicket of individual small slender trees.

Pawpaw flowers are insect-pollinated, but fruit production is limited since few if any pollinators are attracted to the flower's faint, or sometimes non-existent scent. The flowers produce an odor similar to that of rotting meat to attract blowflies or carrion beetles for cross pollination. Other insects that are attracted to pawpaw plants include scavenging fruit flies, carrion flies and beetles. Because of difficult pollination, some believe the flowers are self-incompatible.

Pawpaw fruit may be eaten by foxes, opossums, squirrels and raccoons. However, pawpaw leaves and twigs are seldom consumed by rabbits or deer.

The leaves, twigs, and bark of the common pawpaw tree contain natural insecticides known as acetogenins.

Larvae of the zebra swallowtail butterfly feed exclusively on young leaves of the various pawpaw species, but never occur in great numbers on the plants.

Cultivation and uses

Wild-collected fruits of the common pawpaw (Asimina triloba) have long been a favorite treat throughout the tree's extensive native range in eastern North America. Fresh pawpaw fruits are commonly eaten raw; however, they do not store or ship well unless frozen. The fruit pulp is also often used locally in baked dessert recipes, with pawpaw often substituted in many banana-based recipes.

Pawpaws have never been cultivated for fruit on the scale of apples and peaches, but interest in pawpaw cultivation has increased in recent decades. However, only frozen fruit will store or ship well. Other methods of preservation include dehydration, production of jams or jellies, and pressure canning.

The pawpaw is also gaining in popularity among backyard gardeners because of the tree's distinctive growth habit, the appeal of its fresh fruit, and its relatively low maintenance needs once established. The common pawpaw is also of interest in ecological restoration plantings since this tree grows well in wet soil and has a strong tendency to form well-rooted colonial thickets.

The several other species of Asimina have few economic uses.

History

The earliest documentation of pawpaws is in the 1541 report of the Spanish de Soto expedition, who found Native Americans cultivating it east of the Mississippi River. Chilled pawpaw fruit was a favorite dessert of George Washington, and Thomas Jefferson planted it at his home in Virginia, Monticello. The Lewis and Clark Expedition sometimes subsisted on pawpaws during their travels. The common pawpaw was designated as the Ohio state native fruit in 2009.