Dalhousiea

Taxonomy

Dalhousiea N. Wallich ex G. Bentham Commentat. Legum. Gener. 1, 5. Jun 1837; 2: 65, 69. 1838.

Subfamily: Faboideae.
Phylogenetic Number: 3.2.20.
Tribe: Sophoreae.
Group: Baphia.
Species Studied - Species in Genus: 2 studied; 3 in genus.

Description

Fruit: A legume; unilocular; 5.5–9.5 cm long; 1.5–4.5 cm wide; length less than twice as long as width, or 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, or curved (slightly); not plicate; not twisted; asymmetrical; falcate to fusiform, or irregular; with both sutures parallelly curved, or both sutures unequally curved; not inflated; compressed; without beak; tapered at apex; oblique with longitudinal axis of fruit; tapered at base; oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin embellished; margin with thickened sutural areas (slightly); 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; multicolored; mottled; black, or brown; with black overlay, or brown overlay; mottling color combination constant, or variable; with mottling over seed chambers; with surface texture uniform; glabrous; eglandular; without spines; not smooth; with elevated features; veined, or not veined; reticulately veined; not tuberculate; striate; exfoliating in part, or not exfoliating; with cracks; cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 2-layered; without balsamic vesicles; without fibers; without reniform canals; with solid layer over solid layer; coriaceous. Endocarp present; visible; dull; opaque; monochrome; dark brown; smooth and floury-filamentous; without adhering pieces of testa; nonseptate; chartaceous and pulpy; exfoliating in part; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–3; length oblique to fruit length; neither overlapping nor touching; in 1 series. Funiculus 1–2.5 mm long; of 1 length only; flattened; triangular. Aril present; fleshy; when fleshy marginal hilar; entire; covering less than 1/2 of seed; tan.

Seed: 12–25 mm long; 10–24 mm wide; 2.5–11 mm thick; not overgrown; not angular; symmetrical, or asymmetrical; ovate, or irregular; compressed, or flattened; with surface wrinkled; 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, or dull and glossy; not modified by a bloom; colored; monochrome; black to brown (dark); glabrous; not smooth; with elevated features; wrinkled; coriaceous, or chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum through lens and terminating before base of seed; not bifurcating; color of testa; raised. Hilum present; fully concealed; concealed by funicular remnant and aril, or funicular remnant, or aril; without faboid split; larger than punctiform; 1.7–2 mm long; with curved outline; circular, or elliptic; apical at apex of radicle tip; flush; not within corona, halo, or rim. Lens discernible; 1.5–3 mm long; with margins straight; linear; not in groove of raphe; confluent with hilum; flush; same color as testa; black, or brown; not within corona, halo, or rim. Endosperm absent. Cotyledons not smooth; wrinkled; 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; completely concealing radicle; split over radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; orange; inner face flat; glabrous on inner face. Embryonic axis straight; parallel to length of seed; without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; bulbose; lobe tip straight; straight with embryonic axis; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

West tropical Africa (1 sp., around the Gulf of Guinea) and northeastern India and Bangladish (2 spp.).

Old World; Africa and India.

Generic Notes

Only one seed was studied internally.

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.