Subfamily: Faboideae.
Phylogenetic Number: 3.8.02.
Tribe: Robinieae.
Group: Hebestigma.
Species Studied - Species in Genus: 1 studied; 1 in genus.
Fruit: A legume; unilocular; (9–)11–22 cm long; 2–3.7 cm wide; 1.6 cm thick (estimated); 2–9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; without orifice formed by curving of fruit or fruit segments; straight; not plicate; not twisted; symmetrical, or asymmetrical; oblong; with both sutures nearly straight; not inflated; compressed; without beak; 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; ligneous; seed chambers externally invisible; margin not constricted, or constricted; margin slightly constricted along both margins; margin without sulcus; margin plain; wing(s) absent; nonstipitate, or substipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting (somewhat). Replum invisible. Epicarp glossy; monochrome (including striate); brown (dark reddish to greenish); with surface texture uniform; glabrous; eglandular; without spines; not smooth; with recessed features; not veined; not tuberculate; pitted (longitudinal and oblique); not exfoliating; with 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; without balsamic vesicles; without fibers; without reniform canals; solid; ligneous. Endocarp present; visible; dull; opaque; monochrome; tan; below seeds smooth and scurfy (between seeds); without adhering pieces of testa; septate; with septa thicker than paper, firm; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 2–8; length oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; triangular; straight. Aril present; dry; when dry tongue-aril; entire; tan.
Seed: 17–20 mm long; 13–17 mm wide; 5.5–8.5 mm thick; not overgrown; not angular, or angular (somewhat); asymmetrical, or symmetrical (nearly); circular (sub), or ovate, or obovate, or triangular (more or less); 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, or dull; not modified by a bloom; colored; monochrome; brown (to dark reddish brown when older); glabrous; smooth; osseous. 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; punctiform; apical at apex of radicle tip, or subapical to radicle tip; recessed; not within corona, halo, or rim. Lens not discernible. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire 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; not concealing radicle; split over radicle; with lobes; without basal groin formed by lobes; with the interface division terminating at base of radicle; without margins recessed; tan (reddish); inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule well developed; glabrous.
Tribe Robinieae
The genera, generic groups, and related data follow the tribal treatment of Lavin and Sousa (1995; Polhill, 1994a, 1994b), not Polhill and Sousa (1981).