Poecilanthe

Taxonomy

Poecilanthe G. Bentham J. Proc. Linn. Soc., Bot. 4 Suppl.: 80. 7 Mar 1860.

Subfamily: Faboideae.
Phylogenetic Number: 3.7.
Tribe: Millettieae.
Species Studied - Species in Genus: 4 studied; 9 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 3.7–7 cm long; 1.5–3 cm wide; 1 cm thick; 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; not plicate; not twisted; asymmetrical; with 1 straight and 1 curved suture; widest near middle or D-shaped, or widest near apex; not inflated; compressed; without beak; rounded at apex; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; long tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; ligneous; seed chambers externally invisible; margin not constricted; margin without sulcus; margin plain; wing(s) absent; substipitate, or nonstipitate; with the stipe 0.1–4.5 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along both sutures; apical and down (assumed); passive, or active; with valves breaking (mature valves tend to fracture at right angles to sutures (Lewis, 1988)). Replum invisible. Epicarp dull; monochrome; brown (dark reddish); with surface texture uniform; glabrous; eglandular; without spines, or with spines (on some seed chambers); not smooth; with elevated features; veined; reticulately veined; not tuberculate; not exfoliating; without cracks, or with cracks (if dehisced); cracking oblique to fruit length; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; ligneous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; nonseptate, or septate; with septa thin (tissue paper-like), flexible; with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; without wings; entire. Seed(s) 1–4; length parallel with fruit length, or transverse to fruit length; neither overlapping nor touching; in 1 series. Funiculus 0.1–0.5 mm long; of 1 length only; flattened; straight. Aril absent.

Seed: 10–22 mm long; 9–20 mm wide; 2.5 mm thick; not overgrown, or overgrown, 1 seed filling entire fruit cavity (P. amazonica); not angular; asymmetrical, or symmetrical; elliptic, or ovate, or reniform (somewhat); compressed, or flattened; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; with 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; brown (dark); glabrous; not smooth, or smooth; with elevated features; wrinkled; coriaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Raphe not visible. Hilum present; fully concealed; concealed by funicular remnant; without faboid split; punctiform; between cotyledon and radicle lobe; flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons not smooth (slightly 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; not concealing radicle; notched at radicle; without lobes; with the interface division terminating at base of radicle; without margins recessed; brown (reddish); 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; lobe tip straight; deflexed and parallel to cotyledon width; centered between cotyledons; less than 1/2 length of cotyledons. Plumule rudimentary; glabrous.

Distribution

Tropical South America.

New World; South America (tropical); Argentina, Peru, Brazil, Ecuador, and the Guianas.

Generic Notes

Geesink (1981) placed Poecilanthe in the Tephrosieae (now Millettieae), but in Geesink (1984) the genus is transferred to the Robineae without relating Poecilanthe to other genera in the Robineae. Lavin (1987) and Lavin and Sousa (1995) convincingly demonstrated that Poecilanthe does not belong to Robineae and has close affinity to Dalbergieae. Our species count includes P. itapuana G.P. Lewis (1989). Based on published seed-fruit data about the genus and the lack of a monograph or a résumé of this genus, we have omitted from our study fruit and seed data of P. falcata (J. Velloso de Miranda) W.A. Ducke (including P. grandifora G. Bentham). Even with this arbitrary decision, we are still faced with a genus with similar fruits but two distinct seed types: 1) Glossy with hard testa, straight embryonic axis, and seed length at right angles to fruit length in P. effusa (J.E. Huber) W.A. Ducke, P. itapuana G.P. Lewis, and by inference according to Lewis, P. subcordata G. Bentham and 2) dull with thin testa, curved embryonic axis, and seed and fruit length parallel, P. amazonica.

Tribal Notes

Tribe Millettieae

Geesink (1981) treated this tribe, as others before him, under the tribal name Tephroseae, but we now know that its correct name is Millettieae. Recent tribal studies (Geesink, 1981, 1984; Polhill, 1994a, 1994b) have arranged the genera in alphabetical order without phylogenetic numbers. Geesink (1984) monographed tribe Millettieae, and presented descriptive notes about fruits and seeds and in situ fruit and seed drawings. However, we are not entirely following Geesink (1984) for generic parameters because he either questioned the status of many of his new genera or did not make the necessary species transfers. The few new genera which he clearly recognized are being accepted. Lavin et al. (1998) developed a preliminary infratribal classification of six informal groups using phytochrome nucleotides: Millettia group, Lonchocarpus group, Derris group, Tephrosia group, "primitive" group, and Phaseoleae group. Lavin (1987) transferred Sphinctospermum to Millettieae. Lavin and Doyle (1991) carried out cladistic analyses integrating morphological and chloroplast DNA data, and concluded that it is a member of Robineae where we have placed it (now 8.12).