genusAnnona

Annona

Linnaeus

Sp. Pl. 1: 536. 175

,

Gen. Pl. ed. 5, 241. 1754

Common names: Custard-apple soursop alligator-apple
Etymology: native Hispaniolan anon or hanon, given to A. muricata
Treatment appears in FNA Volume 3.
Trees or shrubs, taprooted; trunks buttressed or not buttressed at base. Bark thin, mostly broadly and shallowly fissured, scaly, fissures anastomosing. Shoots slender, stiff, terete; lenticels raised; buds naked. Leaves persistent or deciduous to late deciduous. Leaf blade leathery or membranous, glabrous to pubescent. Inflorescences axillary or supra-axillary, occasionally from axillary buds on main stem or older stems, solitary flowers or fascicles; peduncle bracteolate. Flowers: receptacle convex to ±globose or elongate, elevated; sepals deciduous, 3(-4), smaller than outer petals, valvate in bud; petals 6(-8) in 2 whorls, usually fleshy, those of outer whorl larger, valvate in bud, those of inner whorl more ascending, distinctly smaller or reduced, rarely absent, valvate or imbricate in bud; nectaries present as darker-pigmented, usually corrugate zones adaxially near petal bases; stamens very numerous, packed into ball, club-shaped, curved; connective dilated, hooded or pointed beyond anther sac; pistils numerous, sessile, partially connate to various degrees with at least stigmas distinct; ovules 1(-2) per pistil; style and stigma club-shaped or narrowly conic. Fruits fleshy syncarps, 1 per flower, usually ovoid to nearly globose, surface variable depending on orientation, structure, and relative connation of pistil apices. Seed usually 1 per pistil, ovoid to ellipsoid, beanlike, coat tough, margins various, narrow. x=7.

Distribution

Mostly neotropic, North America, 10 in Africa.

Discussion

Species 110 (2 in the flora).

Key

1 Sepals reniform-cordate; petals ovate, adaxially concave, those of inner whorl at least 2/3 length of outer whorl; syncarp smooth. Annona glabra
1 Sepals deltate; outer petals oblong or lance-oblong, adaxially keeled, abaxially furrowed, those of inner whorl minute; syncarp muricate. Annona squamosa