Eperua

Taxonomy

Eperua J.B.C.F. Aublet Hist. Pl. Guiane 369. t. 142. Jun 1775.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.48.
Tribe: Detarieae.
Group: Brownea.
Species Studied - Species in Genus: 11 studied; 14 in genus.

Description

Fruit: A legume; unilocular; 6–80 cm long; 3.5–55 cm wide; 0.5–30 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; straight to curved; not plicate; not twisted; symmetrical, or asymmetrical; oblong to dolabriform, or falcate; with both sutures parallelly curved, or 1 straight and 1 curved suture; widest near apex; not inflated; flattened; without beak; long tapered at apex to tapered at apex; not stated; tapered at base to rounded at base (nearly); not stated; with the apex and base uniform in texture; ligneous; seed chambers externally visible; margin not constricted; margin without sulcus; margin plain, or embellished; margin with ventrally thickened sutural areas (if not thickened, then winged), or wing(s); wing(s) present, or absent (when absent with ventral suture thickened); wing(s) 2; wing(s) 0.1–6 mm wide; wing(s) valvular; wing(s) on both valves (1 on each valve very close to the suture); stipitate, or substipitate; with the stipe 6–40 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; active; with valves elastically and separately enrolling. Replum invisible. Epicarp dull to glossy; monochrome; blackish brown to brown; with surface texture uniform; glabrous to pubescent and indurate (with reddish hairs); with hairs erect; with simple hairs; eglandular; without spines; not smooth; with elevated features; veined, or not veined; transversely veined relative to fruit length; not tuberculate; rugose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; surface not veined; 2-layered; without balsamic vesicles; without fibers; without reniform canals; with dark solid layer over solid layer (lighter); ligneous. Endocarp present; visible; dull; opaque; monochrome; reddish brown; without adhering pieces of testa; nonseptate; exfoliating, or not exfoliating (partially separating from mesocarp in some spp.); remaining fused to mesocarp and epicarp; entire. Seed(s) 1–2; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–2 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 25–65 mm long; 18–50 mm wide; 10–17 mm thick; not overgrown; not angular; symmetrical; ovate to circular, or oblong; 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 to dull; not modified by a bloom; colored; monochrome; reddish brown to brown; glabrous; not smooth; with elevated features, or recessed features; rugose to shagreen; striate to pitted with small separate pits; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible (encircling seed). Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; 0.1–5 mm long; with curved outline; circular; apical at apex of radicle tip to subapical to radicle tip; raised to flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons not smooth; rugose (on outer surface); 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; completely concealing radicle; entire over radicle; with the interface division terminating at base of radicle; without margins recessed; inner face concave, or flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed to oblique to length of seed, or perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; centered between cotyledons. Plumule rudimentary; glabrous.

Distribution

East tropical South America.

New World; East tropical South America; Brazil and Ecuador.

Generic Notes

The testa of most studied seed was absent or in fragments. Cowan (1975) monographed the genus and described the fruits as having "dorsal margin alate".

Tribal Notes

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.