Psophocarpus

Taxonomy

Psophocarpus N.M.J. de Necker ex A.P. de Candolle Nom. cons. Prodr. 2: 403. Nov (med.) 1825.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.51.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 4 studied; 10 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 1.5–14(–40) cm long (extreme from literature); 0.6–2(–3.5) cm wide; 0.7–1.5 cm thick; 2–9 times longer than wide, or more than 9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx, or deciduous calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight, or curved (slightly); not plicate; not twisted; asymmetrical, or symmetrical; linear to oblong; not inflated; quadrangular; without beak; short tapered at apex, or rounded at apex, or truncate at apex; aligned with longitudinal axis of fruit; rounded at base to truncate at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous to leathery; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain, or embellished; margin with wing(s); wing(s) present; wing(s) 4; wing(s) (1–)2–6(–10) mm wide; wing(s) valvular; wing(s) on both valves (2 on each valve); nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous, or pubescent and indurate; with hairs erect; puberulent; with simple hairs; eglandular; without spines; smooth, or not smooth; with elevated features; not veined; not tuberculate; rarely warty; not exfoliating; with cracks, or without cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 1-layered, or 2-layered; without balsamic vesicles; without fibers; without reniform canals; solid; with solid layer over solid layer; (sub-) ligneous to coriaceous. Endocarp present; visible; dull; opaque; monochrome, or bichrome; tan and brown, or white and brown; cobwebby, scurfy, and smooth; without adhering pieces of testa; septate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; exfoliating in part; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp; entire. Seed(s) 3–21; length parallel with fruit length, or transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; thick; straight. Aril present, or absent; dry; when dry 2-lipped rim-aril; entire; covering less than 1/2 of seed; with tongues (or flap) on lips of 2-lipped rim-aril; with 1 tongue or flap on 1 lip of 2-lipped rim-aril; cream.

Seed: 3–12.5 mm long; 3–12.2 mm wide; 2.5–11 mm thick; not overgrown; angular, or not angular; symmetrical; circular, or elliptic, or irregular, or oblong, or ovate; terete to quadrangular to compressed; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces; without medial ridge on each face. Cuticle not exfoliating; not inflated; not wrinkled. Testa present; without pieces of adhering epicarp; not adhering to endocarp; free from endocarp; glossy to dull; not modified by a bloom; colored; monochrome, or mottled (from literature); black, or brown, or cream, or white, or yellow; with brown overlay; glabrous, or minutely pubescent; smooth, or not smooth (rarely); with elevated features; with 1 longitudinal ridge on each face; coriaceous to chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible, or not visible; from hilum through lens and base of seed to point opposite hilum; not bifurcating; color of testa, or lighter than testa, or darker than testa; brown; recessed. Hilum present; partially concealed; concealed by aril; with faboid split; with the lips of the faboid split the same color as the rest of the hilum, or lighter colored than the rest of the hilum and therefore conspicuous; larger than punctiform; 2.2–5.5 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; flush; within rim, or not within corona, halo, or rim; rim color of testa. Lens discernible; 0.8–1.8 mm long; with margins straight, or curved; linear; circular, or elliptic; not in groove of raphe, or in groove of raphe; confluent with hilum; mounded, or flush; same color as testa, or similar color as testa; darker than testa; black, or brown (dark); not within corona, halo, or rim. Endosperm absent. Cotyledons smooth; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle; similar at apex; partially concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed, or with margin(s) recessed; with 1 margin recessed; recessed on same side as radicle; yellow; inner face flat; glabrous on inner face. Embryonic axis right angled, or oblique; perpendicular to length of seed to oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose, or triangular; lobe tip straight; straight with embryonic axis, or oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed to well developed; glabrous.

Distribution

Native to Africa and widely cultivated through the tropics world wide.

Old World; Africa and Madagascar (native and cultivated in Africa, and only cultivated in other areas).
Tropical worldwide crop (native and cultivated in Africa, and only cultivated in other areas, including the West Indies and Central and South America in the New World and Asia, India, Indochina, the Pacific, and Hawaii in the old World).

Tribal Notes

Tribe Phaseoleae

Bruneau et al. (1995) carried out cladistic analyses of tribe Phaseoleae using chloroplast DNA restriction site data. Their results indicated that the tribe is not monophyletic and that the tribal delimitations between Phaseoleae and Desmodieae (11) and between Phaseoleae and Millettieae (7) are problematic.