Zenkerella

Taxonomy

Zenkerella P.H.W. Taubert In Engler et Prantl, Nat. Pflanzenfam. 3(3): 386. 22 Mai 1894.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.02.
Tribe: Detarieae.
Group: Cynometra.
Species Studied - Species in Genus: 4 studied; 5 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 4–5.5 cm long; 2–4 cm wide; 1–1.5 cm thick; length less than twice as long as width; 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; symmetrical, or asymmetrical; nearly circular, or elliptic, or falcate; with both sutures parallelly curved, or 1 straight and 1 curved suture; widest near middle or D-shaped; not inflated; compressed; without beak; tapered at apex; aligned with longitudinal axis of fruit; rounded 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; stipitate; with the stipe 6–10 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures (initially along ventral margin); passive. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; minutely pubescent and indurate, or glabrous; with hairs erect; with simple hairs; eglandular; without spines; not smooth; with elevated features; veined; transversely veined relative to fruit length; not tuberculate; glandular dotted; 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 to coriaceous. Endocarp present; visible; dull; opaque; monochrome; brown; without adhering pieces of testa; nonseptate; not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 1–2; length transverse to fruit length; neither overlapping nor touching, or touching (in z seeded fruits); in 1 series. Funiculus 0.1–0.5 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 20–40 mm long; 20–30 mm wide; 7–12 mm thick; not overgrown; not angular; asymmetrical; D-shaped to reniform; 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; dull; not modified by a bloom; colored; monochrome; reddish brown; glabrous; not smooth; with elevated features; rugose; chartaceous (or possibly fleshy when fresh). 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; punctiform, or larger than punctiform; 0.1–3 mm long; with straight outline; apical at apex of radicle tip, or apical according to radicle tip but marginal according to seed length; 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 (all but tip concealed); 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; 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 Africa coastal mountains and Gulf of Guinea.

Old World; East Africa (coastal mountains and Gulf of Guinea).

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.