Pseudopiptadenia

Taxonomy

Pseudopiptadenia S. Rauschert Taxon 31: 559. 9 Aug 1982.

Subfamily: Mimosoideae.
Phylogenetic Number: 2.3.24.
Tribe: Mimoseae.
Group: Piptadenia.
Species Studied - Species in Genus: 5 studied; 8 in genus.

Description

Fruit: A legumelegume:
usually dry, dehiscent fruit derived from a single carpel that opens along two longitudinal sutures
; unilocular; 8–55 cm long; 1–6 cm wide; 0.2–0.8 cm thick; 2–9 times longer than wide, or more than 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 to curved; not plicate; twisted, or not twisted; symmetrical; linear to oblong, or moniliform; not inflated; compressed to flattened; without beak; tapered at apex to short tapered at apex to rounded at apex; aligned with longitudinal axis of fruit; short tapered at base; aligned with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous to ligneous; seed chambers externally invisible, or visible; margin not constricted to constricted; margin constricted along both margins to slightly constricted along both margins, or constricted on 1 margin and slightly constricted on the other margin (ventral margin strongly constricted and dorsal slightly); margin without sulcus; margin plain; wing(s) absent; stipitate; with the stipe 5–20 mm long; with all layers dehiscing; splitting along suture(s). Dehiscence of valves along 1 suture (ventrally); medial and up and down; passive, or active; with valves reflexing (both valves or only one). Replum invisible. Epicarp glossy to dull; monochrome; dark brown to brown; with surface texture uniform; glabrous, or pubescent and indurate (only P. brenanii); with hairs erect; with simple hairs; eglandular; without spines; smooth, or not smooth; with elevated features; veined; reticulately veined; not tuberculate; scaly; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present, or absent; surface not veined; 1-layered; without balsamic vesicles; without fibers; without reniform canals; solid; coriaceous to ligneous. Endocarp present; visible; dull; opaque; monochrome; reddish brown to brown; smooth; without adhering pieces of testa; nonseptate (sometimes constricted between seeds); not exfoliating; remaining fused to mesocarp and epicarp; entire. Seed(s) 4–14; length transverse to fruit length to parallel with fruit length; neither overlapping nor touching; in 1 series. Funiculus 7–20 mm long; of 1 length only; filiform; nearly straight, or S-curved to plicate. Aril absent.

Seed: 9–30 mm long; 6–17 mm wide; 0.1 mm thick; not overgrown; not angular; symmetrical; sub circular to elliptic (short), or oblong; flattened; with surface smooth; without visible radicle and cotyledon lobes; without hilar sinus; without umbo on seed faces, or 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; dull, or glossy; not modified by a bloom; colored; monochrome; blackish brown or brown; glabrous; smooth to not smooth (especially over cotyledons); with elevated features, or recessed features; rugose; slightly striate to striate; chartaceous (sometimes nearly transparent, embryo clearly visible within). Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) present; continuous around seed (1–5 mm wide). Raphe not visible. Hilum present; fully concealed; concealed by wing; without faboid split; punctiform; marginal according to radicle tip, or apical at apex of radicle tip to subapical to radicle tip, or apical according to radicle tip but marginal according to seed length (occasionally); flush; not within corona, halo, or rim. Lens not discernible. Endosperm absent. Cotyledons smooth; both outer faces flat; 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; with lobes; with lobes not touching; with the interface division terminating at base of radicle; without margins recessed; inner face flat; glabrous on inner face. Embryonic axis straight to deflexed; parallel to length of seed, or perpendicular to length of seed (occasionally); without a joint evident between the radicle and the cotyledons. Radicle differentiated from cotyledon; straight with embryonic axis; centered between cotyledons. Plumule well developed, or rudimentary; glabrous.

Distribution

Seven species in southeastern Brazil and P. psilostachya (G. Bentham) G.P. Lewis & M.P. de Lima in Amazon and Orinoco basins and the Guianas.

New World; South America (Seven species in southeastern Brazil and P. psilostachya (G. Bentham) G.P. Lewis & M.P. de Lima in Amazon and Orinoco basins and the Guianas); Brazil and Ecuador.

Generic Notes

The seed characters of this segregate genus of Piptadenia clearly separate Pseudopiptadenia (formerly Monoschisma J.P.M. Brenan) from Piptadenia. Lewis and Lima (1991) examined the Old World and New World species of Newtonia (2.3.07) and Pseudopiptadenia. They concluded that the Old World Newtonia species were generically distinct from the New World species and that the New World Newtonia species should be placed in Pseudopiptadenia. They revised Pseudopiptadenia, and the number of species in this genus came from them and not from Lewis and Elias (1981).