Asimina
Fam. Pl. 2: 365. 1763.
Shrubs or small trees, taprooted; trunks straight in arborescent forms. Bark thin, cracking longitudinally (shallowly furrowed in larger trees of Asimina triloba). Shoots: secondary branching sparse to copious, 2-ranked; primary shoots of shrubs usually several, erect to arching or decumbent; lenticels scattered, small, prominent; buds naked. Leaves deciduous. Leaf blade membranous or leathery, glabrous to variously hairy. Inflorescences axillary, on new shoots or from above leaf scars of previous seasons, fascicles; peduncle bracteate or bracteolate. Flowers 1-4 per leaf axil, nodding to nearly erect, becoming enlarged; receptacle convex to ±globose or elongate, elevated; sepals deciduous, 3(-4), nearly distinct, triangular to deltate-ovate, valvate in bud; petals in 2 unequal whorls, each of 3-4 equal members, with prominent veins, imbricate in bud, those of outer whorl larger, thinner than those of inner whorl; nectaries present, usually with differently pigmented, thickened-corrugate zones adaxially near petal bases; stamens very numerous, short-columnar, forming ball; filament short; connective blunt to nearly spheric or cuboid; pistils 2-8(-12), sessile to stipitate, distinct, glabrate; ovules several (sometimes few) in 2 staggered rows. Fruits simple berries, usually 3-5 per flower, spreading from swollen receptacles, unevenly oblong-cylindric, pulpy. Seeds 3-many per pistil, bean-shaped, slightly compressed laterally, coat tough, margins absent. x=9.
Distribution
Subtropical and temperate North America.
Discussion
Species 8 (8 in the flora).
Selected References
Lower Taxa
Key
| 1 | Leaf blade commonly membranous, oblong-obovate to oblanceolate, apex acute to acuminate; flowers maroon, rarely yellow, fetid, from previous year's shoots before or during new leaf emergence; inner petals with saccate base. | > 2 |
| 1 | Leaf blade commonly leathery, linear to obovate, apex acute to broadly rounded or notched; flowers white or yellow-white to red or maroon, fetid or sweet-smelling, from previous year's growth or from new shoots. | > 3 |
| 2 | Flowers 2-4(-5) cm diam.; peduncle 1 cm or more at anthesis, hairs dark brown to red-brown; corrugate zone of inner petals distinct. | Asimina triloba |
| 2 | Flowers 1-1.7 cm diam.; peduncle less than 1 cm at anthesis, hairs red-brown to tan; corrugate zone of inner petals indistinct or absent. | Asimina parviflora |
| 3 | Flowers from nodes of previous year's growth, emerging before or with leaves; leaf blade elliptic or oblong, obovate or cuneate, never linear, lance-linear, or oblanceolate; flowers large, sweetly fragrant. | > 4 |
| 3 | Flowers from shoots of current year's growth, emerging after leaves are expanding or full-size, either axillary to new leaves or terminal on short shoots; leaf blade linear to narrowly obovate or spatulate; flowers large to small, fragrant or fetid. | > 5 |
| 4 | Abaxial and adaxial surfaces of young leaf blade densely tomentose, hairs pale blond or tan; fully emerged leaf blade oblong to obovate, margins obscurely revolute, inner petals yellow-white with deep yellow corrugate nectary zone. | Asimina incana |
| 4 | Abaxial surface of young leaf blade densely orange-hairy, adaxial surface sparsely orange-hairy; fully emerged leaf blade narrowly obovate to oblong or elliptic, margins strongly to moderately revolute; inner petals white or yellowish white, rarely pink or cherry red, mostly with deep maroon to purple corrugate zone. | Asimina reticulata |
| 5 | New shoots, petiole, abaxial surface of leaf blade along veins, and peduncle with dense, bright red hairs; new growth with flowers (buds) terminal. | Asimina obovata |
| 5 | New shoots, petiole, abaxial surface of leaf blade, and peduncle glabrous to sparsely hairy; new growth with flowers axillary to new leaves. | > 6 |
| 6 | Mature shrubs seldom more than 0.5m, shoots decumbent to arching; perianth maroon to red, outer petals 1.5-3 cm. | Asimina pygmaea |
| 6 | Mature shrubs seldom less than 1m, shoots erect to nearly erect; perianth white to red or maroon, outer petals 2-8 cm. | > 7 |
| 7 | Leaf blade oblong-oblanceolate to broadly spatulate; expanded flowers reddish, fetid; outer petals 2-2.5 cm; perianth 3-4-merous; Florida. | Asimina tetramera |
| 7 | Leaf blade linear, linear-elliptic, linear-oblanceolate, or narrowly spatulate; expanded flowers mostly with outer petals white or cream and inner petals red or white, sweet-smelling; outer petals 3-8 cm; perianth mostly 3-merous; nFlorida, Georgia, Alabama. | Asimina longifolia |