Dicraeopetalum

Taxonomy

Dicraeopetalum H.A.T. Harms Bot. Jahrb. Syst. 33: 161. 18 Nov 1902.

Subfamily: Faboideae.
Phylogenetic Number: 3.2.33.
Tribe: Sophoreae.
Group: Sophora.
Species Studied - Species in Genus: 2 studied; 3 in genus.

Description

Fruit: A legume; unilocular; 2–8.2 cm long; 1–1.8 cm wide; 0.1–0.35 cm thick; length less than twice as long as width; 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, or asymmetrical; elliptic, or falcate (slightly); with both sutures nearly straight; not inflated; flattened; without beak, or with beak (short); straight; with solid beak the same color and texture as fruit; rounded at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; tapered at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; chartaceous; seed chambers externally visible, or invisible; seed chambers with the raised seed chambers not torulose; margin not constricted, or constricted (rarely); margin constricted along both margins; margin without sulcus; margin plain; wing(s) absent, or present (rarely); wing(s) 1; wing(s) sutural; wing(s) on 1 suture (upper); substipitate; indehiscent. Replum invisible. Epicarp dull; monochrome, or multicolored; mottled; brown; with brown overlay (darker); mottling color combination constant; with surface texture uniform; pubescent and indurate; with hairs erect, or appressed; with 1 type of pubescence; puberulent; with pubescence golden; with pubescence uniformly distributed; with simple hairs, or glandular hairs; pliable; with hair bases plain; eglandular, or glandular; with glandular hairs, or dots; distributed over entire fruit; 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; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; chartaceous. Endocarp present; visible; dull; opaque; monochrome; tan; floury-filamentous and smooth; without adhering pieces of testa; nonseptate; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–2; length parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus of 1 length only; filiform; straight. Aril present; dry; when dry very slight rim-aril; entire; without tongue (or flap) on lips of 2-lipped rim-aril; white.

Seed: 5–7 mm long; 3.5–4 mm wide; 1.8–2.2 mm thick; not overgrown; not angular; symmetrical; elliptic, or reniform; 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, or mottled; with frequent mottles; brown; with brown overlay (darker); glabrous; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum through lens to base of seed and terminating; not bifurcating; darker than testa; brown; flush. Hilum present; visible; with faboid split; with the lips of the faboid split the same color as the rest of the hilum; larger than punctiform; 0.5–1 mm long; with curved outline; elliptic; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color darker than testa. Lens discernible; 0.8–2.5 mm long; with margins straight, or curved; narrowly triangular; ovate; not in groove of raphe; confluent with hilum; recessed; similar color as testa; darker than testa; brown; not within corona, halo, or rim. Endosperm absent. Cotyledons smooth, or not smooth; sulcate; 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; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; yellow; inner face flat; glabrous on inner face. Embryonic axis oblique; perpendicular to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; linear; lobe tip curved; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Ethiopa to northern Kenya and southern Madagascar
.
Old World; Africa and Madagascar.

Generic Notes

Polhill (1981b) noted that Dicraeopetalum perhaps is congeneric with Lovanafia M. Peltier (2.33), and Yakovlev (1977), Polhill (1994a, 1994b), and Du Puy et al. (2002) included Lovanafia in Dicraeopetalum. We also have included Lovanafia (a native of Madagascar) in Dicraeopetalum.

Tribal Notes

Tribe Sophoreae

Polhill (1981b) stated that the Sophoreae s.l. is a tribe of convenience between the Caesalpinioideae and the bulk of the Papilionoideae, sharply defined from neither. He transferred four genera from Sophoreae into the Swartzieae (1), Amburana (3.1.15), Ateleia (3.1.13), Cyathostegia (3.1.14), and Holocalyx (3.1.12), following Herendeen's (1995) cladistic analyses. Herendeen performed cladistic analyses for all Swartzieae genera, sensu Cowan (1981), 19 Sophoreae genera, and three Caesalpinioideae genera. He concluded that Swartzieae is polyphyletic and that it should be disbanded and its genera transferred to Sophoreae. Preliminary rbcL data (Doyle et al. 1997) supported his conclusions.