Bikinia

Taxonomy

Bikinia J.J. Wieringa Agric. Univ. Wageningen Pap. 99–4: 187. 30 Sep 1999.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.58A.
Tribe: Detarieae.
Group: Berlinia.
Species Studied - Species in Genus: 1 studied; 10 in genus.

Description

Fruit: A legume; unilocular; 4–21 cm long; 2.2–8.5 cm wide; 0.2–0.9 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; not plicate; not twisted; symmetrical, or asymmetrical; obovate to oblong, or obtriangular (narrowly, rarely); with 1 straight and 1 curved suture, or both sutures unequally curved; widest near apex; not inflated; compressed; with beak; straight, or hooked (0.5–16 mm long); with solid beak the same color and texture as fruit; short tapered at apex to blunt at apex, or rounded at apex; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; rounded at base; oblique with longitudinal axis of fruit to right angled with longitudinal axis of fruit; with the apex and base uniform in texture; seed chambers externally invisible; margin not constricted; margin without sulcus; margin embellished; margin with wing(s); wing(s) present; wing(s) 2; wing(s) 1.5–20 mm wide; wing(s) sutural; wing(s) on 1 suture (on upper suture); stipitate to substipitate; with the stipe 4–17 mm long; with all layers dehiscing (assumed); splitting along suture(s). Dehiscence of valves along both sutures (assumed); passive. Replum invisible. Epicarp dull, or glossy; monochrome; brown, or green (yellowish); with surface texture uniform; pubescent and indurate, or glabrous to glabrate (with a few sparse hairs); with hairs erect, or appressed; with 1 type of pubescence, or 2 types of pubescence, or 3 types of pubescence; velutinous (unform in length or mixed short and long), or strigose, or puberulent, or villous (rarely and sparsely); with pubescence brown; with pubescence uniformly distributed; with simple hairs; stiff, or pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; longitudinally veined relative to fruit length (30–60% down from the upper suture); not tuberculate; sometimes striate (in the upper half), or papillose; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Seed(s) 1–3; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 3 mm long; of 1 length only; triangular. Aril absent.

Seed: 16–38 mm long; 13–30 mm wide; 3–9 mm thick; overgrown, 1 seed filling entire fruit cavity; not angular; symmetrical; broadly elliptic to circular; flattened; with surface grooved; oblique (radiating from the center of the face); 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; bichrome (darker brown around the edge and lighter brown in the center), or monochrome; brown to dark brown or purplish brown; glabrous; not smooth; with recessed features; grooved (radiating from the center of the face); membraneous (breaking easily and lost). 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; 2.5–3 mm long; with curved outline; elliptic; apical at apex of radicle tip; flush to raised (slightly); not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons smooth; slightly 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; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; purplish brown, or purple, or red; inner face flat and concave (at the center below the plumule); pubescent on inner face; pubescent below plumule. Embryonic axis parallel; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Rain forest of western central Africa (Wieringa 1999Wieringa 1999:
Wieringa JJ. 1999. Monopetalanthus exit: A systematic study of Aphanocalyx, Bikinia, Icuria, Michelsonia and Tetraberlinia (Leguminosae, Caesalpinioideae). Wageningen Agricvultural Papers 99-4:1&-320.).

Old World; Africa (Guineo-Congolian forests).
 

Generic Notes

Wieringa (1999) erected this genus to accomodate seven former species of Monopetalanthus H.A.T. Harms and four new species. Gervais and Bruneau (2002) assessed Wieringa's classification using molecular techniques, and their results agreed, in general, with those of Wieringa (1999). No fruits were available for study, so the fruit data were extracted from Wieringa (1999). Only the seeds of B. durandii (F. Hallé & D. Normand) J.J. Weiringa were examined.

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.