Bolusia

Taxonomy

Bolusia G. Bentham Hooker's Icon. Pl. 12: 57. Dec 1873.

Subfamily: Faboideae.
Phylogenetic Number: 3.27.08.
Tribe: Crotalarieae.
Species Studied - Species in Genus: 3 studied; 5 in genus.

Description

Fruit: A legume; unilocular; 2.5–4 cm long; 0.5–1 cm wide; 0.5–0.6 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; asymmetrical; oblong (fusiform or clavate); with both sutures nearly straight; inflated (like most Crotalaria (27.07) spp.); compressed; without beak; short tapered at apex to rounded at apex; aligned with longitudinal axis of fruit; short tapered at base to rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves enrolling, or twisting. Replum invisible. Epicarp dull; monochrome; tan; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined; faintly reticulately veined; not tuberculate; faintly wrinkled; not exfoliating; without cracks, or with cracks (with age); cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thin; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; (sub-) ligneous. Endocarp present; visible; glossy; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 5–8 (estimated); length parallel with fruit length, or transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1–1.5 mm long; of 1 length only; filiform; hooked. Aril absent.

Seed: 2.5–4 mm long; 2.5–3 mm wide; 1 mm thick; not overgrown; not angular; asymmetrical; circular (but with deep hilar sinus); compressed; with visible radicle and cotyledon lobes; without external groove between radicle and cotyledon lobes; with shallow hilar sinus; with 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; streaked and mottled, or monochrome (when immature); with frequent mottles; with frequent streaks; tan; with brown overlay (ish gray); glabrous; not smooth; with elevated features; tuberculate (with tiny white tubercules especially along margin of seed); coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by radicle lobe (hilum in deep sinus), or wing; without faboid split; punctiform; between cotyledon and radicle lobe (in deep hilar sinus); flush; not within corona, halo, or rim. Lens discernible; with margins straight, or curved; apparently oblong; apparently oblong; not in groove of raphe; adjacent to hilum; 0.2 mm from hilum; mounded (well developed and blocking hilar sinus); same color as testa; not within corona, halo, or rim. Endosperm present; thin; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to testa. 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 (barely covering part of radicle near base), or not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; with margin(s) recessed; yellow; inner face flat; glabrous on inner face. Embryonic axis deflexed; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip hooked; deflexed and parallel to cotyledon length; centered between cotyledons; 1/2 to nearly length of cotyledons. Plumule moderately developed; glabrous.

Distribution

Africa (South of the equator).

Old World; Africa (south of the equator).

Tribal Notes

Tribe Crotalarieae

Polhill (1981q) broadly defined tribe Crotalarieae with two generic groups. The first group, without a two-lipped calyx, formed a tight cluster around Lebeckia (3.27.10) in southern Africa. The second group, with a two-lipped calyx, had more scattered distributions and uncertain affinities. Van Wyk (1991) followed Polhill (1981q), and transferred Argyrolobium (3.30.03) from Genisteae (3.30) to the second group. Crotalarieae and related tribes are rich in alkaloids which have been extensively studied in the last decade (Hussain et al. 1988; Van Wyk and Verdoorn, 1989a, 1989b, 1989c, 1990, 1991a, 1991b; Van Wyk et al., 1989, 1993; Verdoorn and Van Wyk, 1990, 1991). Polhill (1994a, 1994b) and Van Wyk and Schutte (1995a), using chemical and morphological data, restricted Crotalarieae to the genera without a two-lipped calyx, and transferred those with a two-lipped calyx to Genisteae, Anarthrophyllum (3.30.06), Argyrolobium (3.30.03), Dichilus (3.30.02), Melolobium (3.30.01), and Sellocharis (3.30.07), except Lebeckia. They also more or less inverted the generic order within the first group according to Van Wyk and Schutte's cladistic analysis for the genera of Crotalarieae, in the narrow sense.