Elephantorrhiza

Taxonomy

Elephantorrhiza G. Bentham J. Bot. Hooker 4: 344. Dec 1841.

Subfamily: Mimosoideae.
Phylogenetic Number: 2.3.13.
Tribe: Mimoseae.
Group: Entada.
Species Studied - Species in Genus: 5 studied; 9 in genus.

Description

Fruit: A legume; unilocular; (5–)8.5–45 cm long; 1.3–7 cm wide; 0.05–0.1 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, or curved; not plicate; not twisted; symmetrical, or asymmetrical; oblong to linear, or falcate; with both sutures parallelly curved; not inflated; compressed to flattened (nearly); without beak; rounded at apex to tapered at apex; aligned with longitudinal axis of fruit; rounded at base to tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous to ligneous; seed chambers externally visible, or invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 5–10 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down to medial and up and down; passive. Replum visible. Epicarp dull; monochrome; dark to blackish or dark reddish to purplish brown; with surface texture uniform; glabrous; eglandular; without spines; not smooth; not veined, or veined (prominently to obscurely); transversely veined relative to fruit length; not tuberculate; exfoliating (often in large segments); 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 to subseptate; not exfoliating; entire. Seed(s) 10–12; length transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1.5 mm long; of 1 length only; thick; curved. Aril absent.

Seed: 9–26 mm long; 8–18 mm wide; 3.5–13 mm thick; not overgrown; not angular; symmetrical; elliptic to circular, or quadrangular (tending to quadrangular); compressed to terete (nearly); with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; with umbo on seed faces (when compressed, with umbo centered in areola), or without umbo on seed faces (when nearly terete); 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; black (with white to tan patches of endocarp or enclosed by coriaceous endocarp tissue); glabrous; not smooth; with minutely sculptured elevated features and recessed features; rugose; pitted with small separate pits; osseous. Pleurogram present, or absent (only E. sp.); 90 %. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; without faboid split; punctiform to larger than punctiform; with curved outline; minutely elliptic; 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; adnate to testa. Cotyledons smooth; both outer faces flat; both the same thickness; both more or less of equal length; not folded; margin entire 180 degrees from base of radicle to not entire 180 degrees from base of radicle; similar at apex; completely concealing radicle; 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; straight with embryonic axis; centered between cotyledons. Plumule moderately developed; glabrous.

Distribution

Generic Notes

Elephantorrhiza species (C and G) is an anomaly: The only studied species in the genus with pleurogrammatic seeds. In all other seed and fruit characters, this is a species of Elephantorrhiza. It is incorrectly identified as E. goetzei (H.A.T. Harms) H.A.T. Harms; was collected by Munro, 1909, in Africa; and is deposited in the carpology collection of the British Museum (Natural History). Ross (1974, 1977a) has studied this genus.