Subfamily: Faboideae.
Phylogenetic Number: 3.10.82.
Tribe: Phaseoleae.
Subtribe: Cajaninae.
Species Studied - Species in Genus: 2 studied; 6 in genus.
Fruit: A legume; unilocular; 1.9 cm long; 0.8 cm wide; 0.5 cm thick; length less than twice as long as width, or 2–9 times longer than wide; with deciduous androecial sheath; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; asymmetrical; fusiform, or reniform; with both sutures unequally curved, or both sutures parallelly curved; not inflated; compressed; with beak; straight, or declined; with solid beak the same color and texture as fruit; tapered at apex to short tapered at apex; aligned 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; coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; assumed apical and down; active; with valves breaking. Replum invisible. Epicarp dull; monochrome; brown to yellow; with surface texture uniform; pubescent and indurate; with hairs erect; with 2 types of pubescence; puberulent; with pubescence golden; with pubescence uniformly distributed; with simple hairs and glandular hairs; pliable; with hair bases swollen and plain; glandular; with glandular hairs; without spines; smooth, or not smooth; with elevated features; veined, or not veined; reticulately veined; not tuberculate; glandular dotted; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; 1-layered; without balsamic vesicles; without fibers; without reniform canals; mealy; chartaceous. Endocarp present; visible; dull; opaque; mottled; with mottling more or less uniform (dark); with tan overlay; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1, or 2; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; flattened; triangular. Aril present; dry; when dry 2-lipped rim-aril; entire; without tongue (or flap) on lips of 2-lipped rim-aril, or 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, or white.
Seed: 6–9.5 mm long; 4–6 mm wide; 3–5.5 mm thick; not overgrown; not angular; symmetrical; reniform; terete; 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; dull; not modified by a bloom; colored; mottled; with frequent mottles; dark brown, or green; with black overlay, or brown overlay; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 1–2 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color of testa. Lens discernible; 0.7–1 mm long; with margins curved; elliptic; not in groove of raphe; confluent with hilum; flush; dissimilar color from testa; darker than testa; black; not within corona, halo, or rim. Endosperm present; trace; not pluglike and not resembling tip of radicle; restricted to region of embryo; adnate to testa. 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; with margin(s) recessed, or without margins recessed; with 1 margin recessed; recessed on same side as radicle; pale tan; 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; linear; lobe tip straight; deflexed and parallel to cotyledon length, or oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule moderately developed; glabrous.