Lebeckia

Taxonomy

Lebeckia C.P. Thunberg Nova Gen. 139. 3 Jun 1800; 122. 1800. 3 Jun 1800.

Subfamily: Faboideae.
Phylogenetic Number: 3.27.10.
Tribe: Crotalarieae.
Species Studied - Species in Genus: 14 studied; ca. 35 in genus.

Description

Fruit: A legume; unilocular; 1.2–6 cm long; 0.2–1.3 cm wide; 0.25 cm thick; length less than twice as long as width, or 2–9 times longer than wide, or more than 9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent calyx, or deciduous calyx; with calyx shorter than fruit; without orifice formed by curving of fruit or fruit segments; straight to curved; not plicate; not twisted; asymmetrical, or symmetrical; linear, or oblong, or elliptic (oblong); with both sutures parallelly curved to both sutures unequally curved; not inflated to inflated; flattened to terete; without beak; short tapered at apex to rounded at apex; aligned with longitudinal axis of fruit; tapered at base to rounded at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; membranous to coriaceous; seed chambers externally visible; seed chambers with the raised seed chambers torulose, or not torulose; margin not constricted; margin without sulcus; margin plain, or embellished; margin with wing(s); wing(s) present, or absent; wing(s) 1; wing(s) 1–2 mm wide; wing(s) sutural; wing(s) on 1 suture; stipitate, or substipitate; with the stipe 0.1–30 mm long; with all layers dehiscing, or indehiscent; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome; reddish brown, or tan; with surface texture uniform; glabrous, or pubescent and indurate; with hairs appressed; with 1 type of pubescence; with pubescence gray; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; not exfoliating; without cracks; 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; coriaceous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth and cobwebby (smooth below seeds and cobwebby between seeds and in areas without seeds); without adhering pieces of testa; septate, or nonseptate; with septa thin (tissue paper-like), flexible; with septa eglandular; coriaceous to chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp, or without wings; entire. Seed(s) 1–8; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; thick; straight. Aril absent.

Seed: 3–4 mm long; 1.7–2.2 mm wide; 1.2–1.5 mm thick; not overgrown; not angular to angular; asymmetrical; obliquely cordate, or oblong (reniform), or rectangular, or reniform; compressed; with visible radicle and cotyledon lobes (barely); without external groove between radicle and cotyledon lobes; 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, or mottled and streaked; with frequent mottles; with frequent streaks; tan; with brown overlay (dark reddish to purplish); glabrous; smooth, or not smooth; with elevated features; faintly warty; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform; between cotyledon and radicle lobe; recessed; within rim, within halo, and within corona, or within rim; corona color darker than testa; halo of testa; rim color of testa, or darker than testa. Lens discernible; 0.7–1 mm long; with margins straight, or curved; wedge-shaped (elongated and ending or not in circular area); circular (above elongated wedge-shape); not in groove of raphe; adjacent to hilum; mounded; dissimilar color from testa; darker than testa; reddish to orangish to dark brown; not within corona, halo, or rim. Endosperm present; thick; not pluglike and not resembling tip of radicle; covering entire embryo; adnate to embryo. 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; not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; tan; 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; bulbose; deflexed and parallel to cotyledon width to deflexed and parallel to cotyledon length; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary, or moderately developed; glabrous.

Distribution

Namibia, Botswana, and South Africa (Cape Province).

Old World; Africa (Namibia, Botswana, South Africa).

Generic Notes

Polhill (1981q), noted that Lebeckia is "virtually indistinguishable" from Spartidum (27.04). Number of species and distribution taken from Van Wyk (1991) and Van Wyk and Schutte (1994).

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.