Subfamily: Mimosoideae.
Phylogenetic Number: 2.3.04.
Tribe: Mimoseae.
Group: Newtonia.
Species Studied - Species in Genus: 1 studied; 1 in genus.
Fruit: A legume; unilocular; 60–75 cm long; 3.5–4 cm wide; 0.2–0.3 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; not plicate; not twisted; asymmetrical; linear; not inflated; compressed; without beak; rounded at apex; aligned with longitudinal axis of fruit; short tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along 1 suture, or both sutures (dehiscing and reflexing ventrally first, eventually opening along dorsal suture); medial and up and down; active, or passive; with valves occassionally twisting. Replum invisible. Epicarp dull, or glossy; monochrome; brown; with surface texture uniform; pubescent but soon deciduous; with hairs erect; velutinous; with simple hairs; eglandular; without spines; not smooth; with elevated features; faintly veined (after dehiscence of hairs); reticulately veined; not tuberculate; exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 1-layered; without balsamic vesicles; with fibers; without reniform canals; fibrous throughout; ligneous. Endocarp present; visible; dull; opaque; monochrome; brown; smooth; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) unknown number; length parallel with fruit length; overlapping; in 1 series. Funiculus ca. 50 mm long; of 1 length only; filiform; S-curved. Aril absent.
Seed: 100–110 mm long; 24–30 mm wide; 1 mm thick; not overgrown; not angular; symmetrical; oblong; 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 (occasionally with patches of lighter brown); brown; with light brown overlay; glabrous; not smooth; with elevated features; rugose; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) present; continuous around seed (2–20 mm wide (20 mm wide at each end)). Raphe not visible. Hilum present; fully concealed; concealed by wing; without faboid split; punctiform (occluded by wing); marginal according to radicle tip; flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons smooth; both outer faces flat; both the same thickness; both more or less of equal length; not folded; margin not entire 180 degrees from base of radicle; wavy; 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; parallel 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.