Subfamily: Mimosoideae.
Phylogenetic Number: 2.3.05.
Tribe: Mimoseae.
Group: Newtonia.
Species Studied - Species in Genus: 1 studied; 1 in genus.
Fruit: A legume; unilocular; 21–23 cm long; 1.3–1.5 cm wide; 0.1–0.2 cm thick; more than 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 to curved; not plicate; not twisted; asymmetrical; linear; not inflated; flattened; without beak; rounded 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; coriaceous; seed chambers externally visible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe up to 30 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; passive. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; faintly veined; reticulately veined; not tuberculate; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp absent. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; not exfoliating; entire. Seed(s) 11–16; length parallel with fruit length; overlapping; in 1 series. Funiculus 2 mm long; of 1 length only; filiform; hooked. Aril absent.
Seed: 16 mm long; 12 mm wide; 1 mm thick; not overgrown; not angular; symmetrical; oblong to elliptic; flattened; 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; not modified by a bloom; colored; mottled; reddish brown (on wing); with dark brown overlay (body); glabrous; not smooth; with elevated features; rugose; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) present; continuous around seed (up to 4.5 mm wide (widest at each end)). Raphe not visible. Hilum present; fully concealed; concealed by wing; without faboid split; punctiform; apical according to radicle tip but marginal according to seed length; flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons smooth; outer face of one cotyledon flat and other cotyledon 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; notched at radicle; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; straight with embryonic axis; centered between cotyledons. Plumule rudimentary; glabrous.