Isoberlinia

Taxonomy

Isoberlinia W.G. Craib & O. Stapf ex J.H. Holland Bull. Misc. Inform. Addit. Ser. 9: 266. 1911.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.64.
Tribe: Detarieae.
Group: Berlinia.
Species Studied - Species in Genus: 4 studied; 5 in genus.

Description

Fruit: A legume; unilocular; 15–35 cm long; 5–9.3 cm wide; 1–2 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; asymmetrical; oblong; not inflated; flattened; without beak; tapered at apex; right-angled with longitudinal axis of fruit; rounded at base; right angled with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally visible, or invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 6–35 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; active; with valves elastically or explosively and separately enrolling. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; glabrous to pubescent and indurate (densely velvety reddish brown to brown or gray); with hairs erect; with simple hairs; eglandular; without spines; not smooth; with elevated features; veined; obliquely veined relative to fruit length, or transversely veined relative to fruit length and reticulately veined; not tuberculate; lenticular (in glabrous species); 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; monochrome; brown; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 5–6; length slightly oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–2.5 mm long; of 1 length only; flattened; straight. Aril absent.

Seed: 25–33 mm long; 18–30 mm wide; 6–7 mm thick; not overgrown; not angular; symmetrical; ovate to 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; dull; not modified by a bloom; colored; monochrome; brown; glabrous; not smooth; with elevated features; faintly rugose; chartaceous. 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; 0.1–5 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, or notched at radicle (only); 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.

Distribution

East coast of Africa and Sudan to Zambezi.

Old World; East coast Africa (including Sudan to Zambezi).

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.