Family: Anonaceae-The Custard Apple Family
Description: Asimina (Pawpaw)
The Pawpaw is a small, deciduous tree that may grow 5-10 meters high (Layne, 1996) and exists in clumps or thickets. According to Duncan and Duncan, the trees are typically a "pyrimidal shape, straight trunk, and dark green, long, drooping leaves" (Duncan and Duncan, 1988). Pawpaws exist as either shrubs or trees, with fruits being "irregularly, cylindrical-shaped berries" (Duncan and Duncan, 1988). Asimina is the only member of the Anonaceae family existing in temperate North America, mostly in the southeast, and the others existing in more tropical climates (Takhtajan, 1997).
(2)A. incarna (Flag Pawpaw)
(3)A. longifolia (Narrow-leafed Pawpaw)
(5)A. parviflora (Small-fruited Pawpaw, Dwarf Pawpaw)
(9)A. tetramera (Opossum Pawpaw)
(10)A. triloba (Pawpaw, Papaw, Paw Paw, Indiana Banana)
(11)A. X nashii
The following is an artificial key to the species of Asimina. It contains didtinguishing characteristics of those species found in the southeasten United States.
flowers reddish, with a fetid aroma; inner petals saccate-based, impressed veiny,
but not corrugate within; shrubs or trees of rich woods and river bottoms.
or reddish-brown hairy.........Species A. triloba.
b. Flowers 1-1.7 cm broad; peduncles less than one cm long at anthesis, usually so short
as to make flowers appear sub-sessile, densely ferrugineous-hairy or tan-hairy
........................................................Species A. parviflora.
years leaves; leaves oval or oblong, obovate, or cuneate--- never linear.
tan-tomentose; leaves obscurely revolute, oblong to obovate, obtuse to broadly rounded;
outer petals white, narrowly oblong to ovate, flat to wavy margined, 3.5-10 cm long;
inner petals yellowish-white with deep yellow corrugate zone............A. speciosa.
densely so; fully emerged leaves evidently revolute, cuneate to oblong, acute to broadly
rounded; outer petals 2.5-6 cm long, oblong to ovate, white, flat to wavy margined; inner
petals white or yellowish-white, or pink, with deep maroon to purple corrugate zone.
oblong-ovate, broadly rounded to broadly acute, seldom more than 6 cm long; bark of
upper portions of old wood gray to gray-brown.............A. reticulata.
b. Leaves deep green, oblong to oblong-lanceolate (rarely spatulate), obtuse to braodly
acute, seldom less than 6 cm long; bark of upper portions of old wood reddish-brown
with raised pale lenticels.......................................................A. X nashii.
or terminating new shoot growth.
flower buds, if present, always terminal on new growth....A. grandiflora.
b. New shoots, petioles, lower leaf surfaces, and penduncles glabrous to sparsely hairy;
new growth with flowers axillary to shoot leaves.
*Shrubs seldom in excess of 0.5 meters tall with decumbent to arching, sparsely
branched, shoots; perianth maroon to reddish, outer petals seldom longer than 3 cm
; leaves sub-erect, elliptic-oblong to spatulate; flowers nutant, secund....A.
*Shrubs seldom less than 1 meter tall with erect to sub-erect, variously branched
shoots; leaves oblong-elliptic or oblong-oblanceolate to broadly spatulate.
-Expanded flowers fetid, less than 3.5 cm broad; reddish; tall shrubs of s.e.
peninsular Florida......................A. tetramera.
-Expanded flowers more than 3.5 cm broad, fragrant, the outer petals white, pink,
or with maroon streaks; shrubs of north-central Florida......A. X nashii
*Leaves linear, linear-elliptic, oblanceolate, or narrowly spatulate
Reference: (Kral, 1959)
Members of this species are native to southeastern United States and are often planted as ornamental trees and praised for their sweet, custard-like fruits (The Pawpaw Foundation).
Asimina was proposed first by Adanson. Most European and American botanists looked to William Bartram's book with specimens and illustrations which were then showing five undescribed species of Asimina(Kral, 1959). Even though most species are limited to the extreme southeastern part of the United States, A. parviflora is found as far north as Virginia and A. trilobaoccurs as far north as southern Michigan and even as far west as Oklahoma (Callaway, 1990).
Extracts of the seeds and bark contain the alkaloids asiminine and analobine and were once used as a type of medicine (Callaway, 1990). More recently, there have been discoveries of another alkaloid, asmicin, which has properties of a pesticide. The highest concentrations are found in bark (Callaway, 1990).
The Pawpaw is cultivated for its rich, pulpy, banana-custard-like fruit. The pawpaw is now being developed as a new fruit crop in certain areas of the country. Pawpaw is an excellent food source (Layne, 1996) and is very attractive with its intense tropical flavor and aroma. Click for more about Pawpaw fruit and gardening.
Special thanks to Bryan McLucas for all of the help with the technical problems and Elizabeth Skillen for scanning images of A. triloba and A. parviflora!