Subfamily: Faboideae.
Phylogenetic Number: 3.10.78.
Tribe: Phaseoleae.
Subtribe: Cajaninae.
Species Studied - Species in Genus: 2 studied; 6 in genus.
Fruit: A legume; unilocular; 1.7–2 cm long; 0.5–0.7 cm wide; 0.4–0.5 cm thick; 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx, or persistent calyx; with calyx longer than fruit; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical; narrowly elliptic; not inflated; terete; with beak; straight (2–3 mm long); with solid beak the same color and texture as fruit; tapered at apex; aligned with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous; seed chambers externally invisible; margin constricted; margin without sulcus; margin plain; 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; brown; with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; velutinous; with pubescence white or yellowish white; with pubescence uniformly distributed; with simple hairs (antrorse); pliable; with hair bases swollen (yellow); eglandular; without spines; not smooth; with recessed features; not veined; not tuberculate; obliquely, shallowly grooved; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; glossy; opaque; monochrome; white; 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 ca. 0.5 mm long; flattened; broadly triangular. Aril present; fleshy; when fleshy 2-lipped rim-aril; entire; covering less than 1/2 of seed; without tongue (or flap) on lips of 2-lipped rim-aril.
Seed: 3.6–4.7 mm long; 3–3.7 mm wide; 2.7–3 mm thick; not overgrown; not angular; symmetrical; ovate; 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; dull to glossy; not modified by a bloom; colored; mottled, or monochrome; with frequent mottles; black, or brown (dark); with brown overlay; glabrous; smooth; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. 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; larger than punctiform; 1.5–2.8 mm long; with curved outline; elliptic; marginal according to radicle tip; recessed; within halo, or not within corona, halo, or rim; halo lighter than testa. Lens discernible; 0.5–0.8 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; recessed, or flush; same color as testa; black, or brown; within halo; halo color lighter than testa. Endosperm absent. Cotyledons smooth; with 2 outer faces on each cotyledon, one flat and the other 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; not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; dark brown; inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; with a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.
The status of Chrysoscias is ambiguous. It has been maintained as a genus (Lackey 1981; Polhill 1994b), and synonymized under Rhynchosia (10.80) (Grear 1978; Arnold and De Wet 1993). Pending detailed studies, we have accepted it as a genus.