Dussia

Taxonomy

Dussia C.W.L. Krug & I. Urban ex P.H.W. Taubert In Engler et Prantl, Nat. Pflanzenfam. 3(3): 193. Nov 1892.

Subfamily: Faboideae.
Phylogenetic Number: 3.2.24.
Tribe: Sophoreae.
Group: Dussia.
Species Studied - Species in Genus: 4 studied; 10 in genus.

Description

Fruit: A legume; unilocular; 3–12 cm long; 2–5.5 cm wide; length less than twice as long as width, or 2–9 times longer than wide; with persistent androecial sheath (with or without various petals), or deciduous androecial sheath; with persistent corolla (with or without androecial sheath), or deciduous corolla; with various petals; 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; elliptic, or fusiform; not inflated; compressed; without beak; rounded at apex to tapered at apex; aligned with longitudinal axis of fruit; rounded at base to tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous to ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate, or stipitate; with the stipe 1–5 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; probably medial and up and down; active; with valves enrolling. Replum invisible. Epicarp dull (obscured by indument); with surface texture uniform; pubescent and indurate; with hairs erect; with 1 type of pubescence; velutinous to villous; with pubescence golden, or brown (rust-brown to orangish); with pubescence uniformly distributed; with simple hairs; stiff; with hair bases plain; apparently eglandular; without spines; not smooth; with elevated features; not veined; not tuberculate; rugose, or verrucose-rugose; not exfoliating; without cracks; 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, or empty space (with or without spongy tissue) within solid layer; coriaceous to ligneous. Endocarp present; visible; dull; opaque; mottled; pale yellow; with mottling more or less uniform (dark); with black overlay; rugose; 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; in 1 series. Funiculus 8 mm long; of 1 length only; flattened; long triangular. Aril absent.

Seed: 20–45 mm long; 10–20 mm wide; 10–20 mm thick; not overgrown; angular; symmetrical; mitaform to irregular; terete; 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 infrequent mottles; brown, or red (dark); with black overlay; glabrous; not smooth; with elevated features; rugose; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe visible; from hilum to near base of seed and terminating; not bifurcating; color of testa; raised. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; larger than punctiform; 2–5 mm long; with curved outline; elliptic to fusiform; apical according to radicle tip but marginal according to seed length; recessed; within rim; rim color darker than testa. Lens not discernible. Endosperm absent. Cotyledons not smooth; finely rugose; both outer faces convex; both the same thickness; both more or less of equal length; not folded; margin not entire 180 degrees from base of radicle; notched; similar at apex; completely concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; green to tan; inner face wrinkled; glabrous on inner face. Embryonic axis oblique; oblique to length of seed; without a joint evident between the radicle and the cotyledons. Radicle not differentiated from cotyledon; bulbose; lobe tip straight; oblique to cotyledons; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Southern Mexico, Antilles, and Central America to Peru and Brazil (Amazon basin).

New World; West Indies, Mexico, Central America, and South America; Peru, Brazil, Ecuador, and the Guianas.

Generic Notes

Rudd (1963) monographed Dussia. Some information was taken from that source.

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.