Microcharis

Taxonomy

Microcharis G. Bentham In G. Bentham et J. D. Hooker, Gen. 1: 501. 19 Oct 1865.

Subfamily: Faboideae.
Phylogenetic Number: 3.9.04.
Tribe: Indigofereae.
Species Studied - Species in Genus: 5 studied; 35 in genus.

Description

Fruit: A legume; unilocular; 0.8–3.5 cm long; ca. 0.1 cm wide; ca. 0.1 cm thick; 2–9 times longer than wide, or more than 9 times longer than wide; with deciduous androecial sheath; with deciduous corolla; with persistent 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; terete; without beak, or with beak (Microcharis phyllogramme (R. Vig.) Schrire, Du Puy & Labat (Du Put et al., 2002)); tapered at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; tapered at base to short tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit (45–90 degrees, Microcharis phyllogramme (R. Vig.) Schrire, Du Puy & Labat (Du Put et al., 2002)); with the apex and base uniform in texture; chartaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain, or embellished (Microcharis phyllogramme (R. Vig.) Schrire, Du Puy & Labat (Du Put et al., 2002)); margin with thickened sutural areas (Microcharis phyllogramme (R. Vig.) Schrire, Du Puy & Labat (Du Put et al., 2002)); wing(s) absent; nonstipitate; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down; active; with valves twisting. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; tan to brown; with brown overlay; mottling color combination constant; with surface texture uniform; pubescent and indurate, or glabrous (rqarely, Microcharis asparagoides (P.H.W. Taubert) B.D. Schrire); with hairs appressed; with 1 type of pubescence; sericeous; with pubescence hyaline; with pubescence uniformly distributed; with complex hairs; with T-shaped hairs; pliable; with hair bases plain; eglandular; without spines; smooth; not 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; translucent; monochrome; hyaline; smooth; without adhering pieces of testa; septate, or subseptate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; not exfoliating; remaining fused to epicarp; without wings; entire. Seed(s) 5–16 (Microcharis phyllogramme (R. Vig.) Schrire, Du Puy & Labat (Du Put et al., 2002)), or 20–25; length parallel with fruit length; touching; in 1 series. Funiculus of 1 length only; filiform; straight. Aril absent.

Seed: 1-2 mm long; 0.8–1.4 mm wide; 0.6–0.9 mm thick; not overgrown; angular; symmetrical; quadrangular, or rectangular, or irregular; compressed; with surface smooth; without visible radicle and cotyledon lobes; with shallow 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; glossy; not modified by a bloom; colored; monochrome, or mottled; with frequent mottles; dark to light olive; with brown overlay; glabrous; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; visible, or fully concealed; concealed by aril remnant; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; punctiform to larger than punctiform; 0.06–0.6 mm long; with curved outline; circular to elliptic; flush; not within corona, halo, or rim, or within corona; corona color darker than testa. Lens discernible; 0.16–0.3 mm long; with margins curved; elliptic; not in groove of raphe; confluent with hilum, or adjacent to hilum; 0–0.06 mm from hilum; flush; dissimilar color from testa; darker than testa; brown, or tan; not within corona, halo, or rim. 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; not concealing radicle; entire over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; olive green, or tan; inner face flat; glabrous on inner face. Embryonic axis oblique to length of seed to perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; oblique to cotyledons to perpendicular to cotyledons; not centered between cotyledons (radicle outside 1 cotyledon and inside other, therefore junctions for each cotyledon different); less than 1/2 length of cotyledons to equaling length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Tropical Africa, Madagascar, and the southern Arabian peninsula.

Old World; tropical Africa, Madagascar, and Southwest Asia (southern Arabian peninsula).

Generic Notes

Schrire (1992, 1995) carried out cladistic analyses using morphical characters and chromosome numbers. Two of his conclusions were that Indigastrum (3.9.05) and Microcharis should be separated from Indigofera (3.9.07) as good genera. Polhill (1994a, 1994b) and Du Puy et al. (2002) agreed with his conclusions.

Tribal Notes

Tribe Indigofereae

Schrire (1995) carried out extensive cladistic anaylses with Indigofereae genera and infrageneric taxa of Indigofera (9.07).