Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.80.
Tribe: Detarieae.
Group: Brachystegia.
Species Studied - Species in Genus: 5 studied; 9 in genus.
Fruit: A legume; unilocular; 6–12 cm long; 2.5–4 cm wide; 0.5–0.6 cm thick; 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; curved; not plicate; not twisted; symmetrical, or asymmetrical; oblong, or falcate; with both sutures parallelly curved; not inflated; flattened; without beak; tapered at apex; nearly aligned with longitudinal axis of fruit; rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; active; with valves separately enrolling. Replum invisible. Epicarp dull to glossy; monochrome; reddish brown to dark brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; longitudinally veined relative to fruit length; not tuberculate; exfoliating, or not 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; without fibers; without reniform canals; solid; ligneous. Endocarp present; visible; dull; opaque; bichrome; tan and brown (under seeds); smooth and spongy (smooth and brown under seeds and tannish and spongy around seeds); without adhering pieces of testa; subseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1–6; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–2 mm long; of 1 length only; flattened; straight. Aril absent.
Seed: 15–20 mm long; 10–13 mm wide; 3–5 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; ovate, or irregular; 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; nearly glossy to dull; not modified by a bloom; colored; monochrome; dark brown; glabrous; not smooth; with elevated features; faintly rugose; osseous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; 0.1–2 mm long; with curved outline; elliptic; apical at apex of radicle tip; flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. 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 (only tip exposed); notched at radicle and split over 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; centered between cotyledons. Plumule rudimentary; glabrous.
Tribe Detarieae
Bruneau et al. (2000) carried out extensive phylogenetic analyses of tribes Amherstieae and Detarieae. They concluded that they form a single monophyletic group. Therefore, they supported Polhill's (1995a, 1995b) decision to unite the two tribes.