Rothia

Taxonomy

Rothia C.H. Persoon Nom. cons. Syn. Pl. 2: 638, [659]. Sep 1807.

Subfamily: Faboideae.
Phylogenetic Number: 3.27.02.
Tribe: Crotalarieae.
Species Studied - Species in Genus: 2 studied; 2 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; (1–)3.5–4.5 cm long; 0.15–0.2 cm wide; 0.15–0.17 cm thick; 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; not plicate; not twisted; symmetrical; linear; not inflated; flattened; without beak, or with beak (Du Puy et al., 2002); straight; with solid beak the same color and texture as fruit; tapered at apex; aligned with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; membranous; 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 1 suture; apical and down; active; with valves enrolling (when mature gaping along adaxial suture). Replum invisible. Epicarp dull; monochrome; reddish brown; with surface texture uniform; pubescent and indurate; with hairs appressed; with 1 type of pubescence; with pubescence golden; with simple hairs; 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 absent. Endocarp present; visible; glossy; opaque; monochrome; brown; smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to epicarp; without wings; entire. Seed(s) 15–20 (Du Puy et al., 2002); length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.5–1 mm long; of 1 length only; filiform; contorted. Aril absent.

Seed: 1–1.4 mm long; 0.8–1 mm wide; 0.6–0.7 mm thick; not overgrown; not angular; asymmetrical; mitaform, or reniform (Du Puy et al., 2002); compressed; with visible radicle and cotyledon lobes; 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; glossy; not modified by a bloom; colored; conspicuously to faintly mottled, or monochrome; with frequent mottles; brown, or green, or tan; with purple overlay, or tan overlay; glabrous; smooth; 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 (may be the smallest in the subfamily); between cotyledon and radicle lobe; recessed; within rim (with or without a black patch around rim); rim color of testa. Lens discernible (as large as hilar area (including rim)); with margins curved; circular; not in groove of raphe; confluent with hilum (or nearly so); mounded; dissimilar color from testa; darker than testa; reddish brown; 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; not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; tan, or 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; deflexed and parallel to cotyledon length; not centered between cotyledons (radicle outside 1 cotyledon and inside other, therefore junctions for each cotyledon different); less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Africa (1 sp.) and Baluchistan to Australia (1 sp.).

Old World; Africa, Madagascar, India, Indochina, Indonesia and the Philippines, and Australia.

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.