Lablab

Taxonomy

Lablab M. Adanson Fam. 2: 325. Jul-Aug 1763.

Subfamily: Faboideae.
Phylogenetic Number: 3.10.61.
Tribe: Phaseoleae.
Subtribe: Phaseolinae.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legume; unilocular; 3.7–5 cm long; 1.6–1.8 cm wide; 0.6–0.8 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent 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; irregular; with 1 straight and 1 curved suture, or both sutures unequally curved; widest near middle or D-shaped; not inflated; compressed; with beak; hooked; with solid beak the same color and texture as fruit; short tapered at apex; oblique with longitudinal axis of fruit; tapered at base, or short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous to coriaceous; seed chambers externally visible, or invisible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin embellished; margin with thickened sutural areas, or thickened sutural areas and prickles; wing(s) absent; 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; tan; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; short puberulent; with pubescence white; with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; verrucose-rugose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; trace; surface not veined; 1-layered; without balsamic vesicles; without reniform canals; solid; chartaceous. Endocarp present; visible; glossy; opaque; monochrome; tan to white; smooth; without adhering pieces of testa; subseptate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; exfoliating in part; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 2–4; length oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–2 mm long; of 1 length only; flattened; triangular. Aril present; fleshy; when fleshy hippocrepiform rim-aril; fimbriate; 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: 8–18 mm long; 5.5–11.5 mm wide; 3.8–7.5 mm thick; not overgrown; not angular; asymmetrical; elliptic to irregular to ovate; nearly terete to compressed; with surface smooth; with visible radicle and cotyledon lobes; without external groove between 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; dull; not modified by a bloom; colored; monochrome, or mottled; with infrequent mottles; brown, or cream; with brown overlay (darker); glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by aril; without faboid split; larger than punctiform; 8–12.5 mm long; with straight outline; linear; marginal according to radicle tip; recessed; within corona, or not within corona, halo, or rim; corona color darker than testa. Lens discernible; 1.8–2 mm long; with margins straight, or curved; linear; elliptic; not in groove of raphe; confluent with hilum; mounded; similar color as testa, or dissimilar color from testa; darker than testa; brown, or tan; within rim; rim color of testa, or darker than testa. 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; white to tan to brown; inner face flat; glabrous on inner face. Embryonic axis oblique; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip curved; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule well developed; glabrous.

Distribution

Africa, And widely cultivated.

Old World (widely cultivated); Africa and Madagascar.

Worldwide crop.

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.