Leonardoxa

Taxonomy

Leonardoxa A. Aubréville Adansonia ser. 2. 8: 178. 27 Sep 1968.

Subfamily: Caesalpinioideae.
Phylogenetic Number: 1.4.07.
Tribe: Detarieae.
Group: Cynometra.
Species Studied - Species in Genus: 1 studied; 1 in genus.

Description

Fruit: A legume; unilocular; 8–10 cm long; 3–4 cm wide; 0.5–1 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; not plicate; not twisted; symmetrical, or asymmetrical; obovate, or oblong; with both sutures nearly straight, or both sutures parallelly curved, or 1 straight and 1 curved suture; widest near middle or D-shaped to widest near apex; not inflated; flattened; with beak; straight; with solid beak the same color and texture as fruit; short tapered at apex; aligned with longitudinal axis of fruit; tapered at base to rounded at base; aligned with longitudinal axis of fruit to oblique with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally visible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 17–19 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; active; with valves enrolling. Replum invisible. Epicarp dull; monochrome; brown; with surface texture uniform; pubescent and indurate (minutely puberulent with brown hairs 0.1 mm long and visible only at high magnification); with hairs erect; with 1 type of pubescence; eglandular; without spines; not smooth; with elevated features; veined; transversely veined relative to fruit length; not tuberculate; not exfoliating; with cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 2-layered; without balsamic vesicles; with fibers; without reniform canals; with fibers embedded in mealy tissue over solid layer; ligneous. Endocarp present; visible; dull; opaque; monochrome; brown; smooth; without adhering pieces of testa; nonseptate; ligneous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–3; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus ca. 1 mm long; of 1 length only; thick; straight. Aril absent.

Seed: 15–25 mm long; 12–20 mm wide; 2–3 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; ovate, 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; dull; not modified by a bloom; colored; monochrome; dark brown; glabrous; not smooth; with elevated features; rugose (especially on face); coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent, or present (very narrowly so); wing-like around seed. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; ca. 1 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; completely concealing radicle; split over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; brown; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; with 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 moderately developed; glabrous.

Distribution

Guineo-Congolian forest, from Nigeria to the Congo.

Old World; Africa (Guineo-Congolian forest, from Nigeria to the Congo).

Generic Notes

LÉonard (1993) segregated two species from Leonardoxa, L. bequaertii (E.A.J. De Wildeman) A. Aubréville and L. romii (E.A.J. De Wildeman) A. Aubréville, and placed them in the new genus Noramandiodendron (1.4.08A). Brouat et al. (2001) constructed a molecular phylgeny for Leonardoxa and Noramandiodendron and the related genera Brachystegia (1.4.76), Hymenostegia (1.4.09), and Loesenera (1.4.10). They concluded: 1) Noramandiodendron is distinct from Leonardoxa; 2) Leonardoxa is monotypic; and, 3) the morphological and molecular clades are not congruent, suggesting "the possibility of gene flow or introgressive events between parapatric subspecies".

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.