Apocynaceae

Taxonomy

Family name: Apocynaceae Jussieu

Synonym(s): Asclepiadaceae Borkh., nom. cons.; Periplocaceae Schltr., nom. cons.; Plumeriaceae Horan.; Stapeliaceae Horan.; Vincaceae Vest; Willughbeiaceae J. Agardh

Common name(s): dogbane family

*Number of genera/species: 366/5,100

List of genera records in GRIN-Global

Disseminule

fruit or seed

Description

Note, fruits are usually formed from a 2-carpellate, sometimes 1-carpellate by abortion, apocarpous, superior ovary. Follicles and other fruit types, berries or drupes, may occur in pairs.

Fruit dehiscent, usually follicle, paired or solitary, paired follicle may fuse into a “double-follicle”, which splits at maturity along area of fusion. Or, fruit indehiscent, berry (bilocular or unilocular, Whillughbeieae, Tabernaemontaneae, Melodineae, Hunterieae, Carisseae), drupe (Vinceae, Plumerieae, Alyxieae - fleshy or woody), rarely capsule (Allamanda, Craspidospermum, Plectaneia), samaroid drupe (paired, Cameraria, Ceberiopsis), or spiny nutlet (Emicocarpus). Fruits 5–610 mm long.

Follicles usually fusiform or linear, compressed or terete in transection, beaked, paired follicles often fused at their apices until maturation splits them apart, usually many seeded, and not enclosed by floral parts or bracts. Pericarp brown, green, white, and yellow to orange, dull, usually dry, thin or thick, sometimes woody or fleshy. Pericarp glabrous or pubescent, usually smooth, sometimes ornamented or with wings. Seeds usually less than 40 mm long, often compressed, with coma, beaked, with or without wing-like margin, and usually glabrous.

Berries and drupes, apocarpous or syncarpous, globose to ellipsoid, sometimes torulose or moniliform, terete in transection. Berries usually many seeded, sometimes one or few seeded. Drupes usually one seeded, sometimes two or three seeded. Fruits not enclosed by floral parts or bracts. Pericarp bright red, orange, purple, black or blue-black, usually dull, sometimes shiny, usually thick, fleshy, sometimes leathery or woody. Berries often with brightly colored, pulpy, spongy, or fibrous placentas. Drupes with fleshy, pulpy, or fibrous mesocarps and stony or woody endocarps. Fruits usually glabrous, usually smooth, sometimes warty (Hunteria spp.) or with soft prickles (Tabernanthe spp.). Seeds compressed, usually wingless (apically winged, Thevetia, wing-like margin, Cameraria, Cerberiopsis, Ochrosia), and without coma.

Capsules occur in three genera, Allamanda, Craspidospermum, and Plectaneia. Capsules dehiscent, septicidal, 30–70 mm long, globose, ovoid, or linear, many seeded. Pericarp brown, woody or fleshy, glabrous, smooth (Craspidospermum), spiny (Allamanda), or with four ribs or wings (Plectaneia). Seeds compressed, winged, and without coma.

Seed usually ovoid, flattened, compressed, or terete in transection, 2–80 mm long, often with a tuft of brown to white hairs at the micropylar end (coma), sometimes chalazal end or both ends, usually wingless, if winged, wing papery, membranous, or fibrous, at one end or both or around the margin. Seed coat black or brown, glabrous, sometimes hairy, smooth or variously sculptured. In some genera, seeds with arils, which are often brightly colored and fleshy, waxy, mucilaginous, or corky (Chilocarpus).

Embryo well developed, partially filling seed, axile or centric, foliate or linear, straight, sometimes bent, often chlorophyllous. Endosperm absent, scanty, or copious, if present oily, in some genera ruminate.

Identification features

Fruit
Type	follicles, capsules, berries, drupes
Size range	5–610 mm long
Shape(s)	usually fusiform to linear, sometimes ellipsoid, oblong, cylindric, obclavate, or pyriform, or rarely globose, torulose, moniliform or triangular (Emicocarpus)
Texture	Follicles, thin or thick walled and woody to papery; berries, fleshy, non-fibrous, mostly without a sclerified layer, placenta pulpy sometimes brightly colored; drupe, thick stringy, pulpy, or fleshy with stony endocarp
Surface relief	usually smooth, sometimes with irregular corky prickles or ridged, winged, or spiny (nutlet, Emicocarpus)
Color(s)	black, blue-black, brown (all shades), red, orange, yellow, green, purple
Unique features	Usually fusiform or linear, beaked, and often paired follicles, which are often fused at their apices until maturation splits them apart, not enclosed by floral parts or bracts and with numerous, compressed, tufted-haired seeds.
Seed
Size range	2–80 mm long
Shape(s)	ovoid, fusiform, ellipsoid, pyriform, globose, cylindrical, oblong, linear, rarely plano-convex, angular, U-shaped (Emicocarpus)
Surface relief	smooth or pitted, ridged, grooved, warty, papillose, tuberculate, crenulate
Color(s)	brown, black
Unique features	Seeds usually less than 40 mm long, often compressed, with coma, beaked, with or without wing-like margin, and usually glabrous. If coma lost, a light, triangular or lens-shaped scar remains.
Other
Embryo	well developed, partially filling seed, axile or centric, foliate or linear, straight, sometimes bent, often chlorophyllous
Nutritive tissue	absent, scanty, or copious, if present oily, ruminate in some genera

Distribution

Mostly tropical and subtropical regions with few temperate species.

Distribution map courtesy of Angiosperm Phylogeny Website.

References

Endress and Bruyns 2000; Flora of North America Editorial Committee 1993+; Kirkbride et al. 2006; Kubitzki et al. 1990+; USDA 1980; Zhengyi et al. 2004+

*The number of genera and species is based on Christenhusz and Byng 2016, which may differ from the number of genera in GRIN-Global.