Paramachaerium

Taxonomy

Paramachaerium W.A. Ducke Arch. Jard. Bot. Rio de Janeiro 4: 86. 1925.

Subfamily: Faboideae.
Phylogenetic Number: 3.4.10.
Tribe: Dalbergieae.
Group: Dalbergia.
Species Studied - Species in Genus: 4 studied; 5 in genus.

Description

Fruit: A legume, or a nutlet; unilocular; 2.5–12 cm long; 2–6 cm wide; 0.7–1 cm thick; 2–9 times longer than wide, or length less than twice as long as width; with deciduous androecial sheath; with deciduous corolla; with deciduous calyx; straight, or curved (slightly); not plicate; not twisted; asymmetrical; oblong, or lanceolate, or falcate, or C-shaped (barely), or samaroid; with both sutures parallelly curved, or both sutures unequally curved, or both sutures nearly straight; not inflated; flattened; without beak; rounded at apex, or short tapered at apex; oblique with longitudinal axis of fruit, or right-angled with longitudinal axis of fruit; short tapered at base, or rounded at base; aligned with longitudinal axis of fruit, or oblique with longitudinal axis of fruit; with the apex and base uniform in texture; coriaceous, or ligneous (especially seed chambers); seed chambers externally visible, or invisible; seed chambers with the raised seed chambers not torulose; margin not constricted; margin without sulcus; margin embellished, or plain; margin with wing(s); wing(s) present, or absent (in P. schomburgkii); wing(s) 1; wing(s) 0.1–100 mm wide; wing(s) samaroid; wing(s) basal; wing(s) on 1 suture; substipitate, or nonstipitate; indehiscent. Replum invisible. Epicarp dull; monochrome; brown (but turning black on drying), or black; with surface texture uniform; glabrate, or pubescent but soon deciduous; with hairs erect; with 1 type of pubescence; pilose, or tomentose; with pubescence brown (reddish); with pubescence uniformly distributed; with simple hairs; pliable; with hair bases plain; eglandular; without spines; not smooth; with elevated features; veined; reticulately veined; not tuberculate; wrinkled; not exfoliating; without cracks; without embedded tissue, much thicker than epicarp, running from base to apex. Mesocarp present; thick (over seed chamber); surface uniformly veined; 2-layered; without balsamic vesicles; with fibers; without reniform canals; with fibers over solid layer; coriaceous, or ligneous. Endocarp present; visible; dull; opaque; monochrome; tan; smooth; without adhering pieces of testa; septate, or nonseptate; with septa thicker than paper, firm (solid); with septa eglandular; chartaceous; not exfoliating; remaining fused to mesocarp and epicarp; with wing(s) extending into epicarp, or without wings (in P. schomburgkii); entire. Seed(s) 1, or 2; length transverse to fruit length; neither overlapping nor touching, or overlapping and touching; in 1 series. Funiculus of 1 length only; straight. Aril absent.

Seed: 1.4 mm long; 0.4 mm wide; 0.3 mm thick; not overgrown; not angular; asymmetrical; linear, or oblong, or reniform (to oblong), or triangular; compressed; with surface smooth; with visible radicle and cotyledon lobes; without external groove between 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; brown (brown to blackish); glabrous; smooth; chartaceous. Pleurogram absent. Pseudopleurogram absent. Fracture lines absent. Rim absent. Wing(s) absent. Endosperm absent. Cotyledons smooth; 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; partially concealing radicle; entire over radicle; without lobes, or with lobes; with lobes not touching; without basal groin formed by 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

Panama, Guyana, and Brazil.

New World; Central America to South America (Guyana and Brazil, Central America (Panama)); Peru, Brazil, Ecuador, and the Guianas.

Generic Notes

Rudd (1981) supplied the count of five species, and we are not using the three species count of Polhill (1981d). Rudd noted, "that the two species, P. schomburgkii and P. ormosioides (W.A. Ducke) W.A. Ducke with the least wing development on the pods which are presumably best adapted to flotation, are reported to occur on periodically inundated land, 'igapó.' Two other species, P. gruberi G.K. Brizicky and P. schunkei V.E. Rudd, with conspicuous wing development, and P. krukovii V.E. Rudd, expected to have winged pods, are found in locations not subject to flooding." Brizicky (1960) presented fruit and seed data for the Panamanian species, P. gruberi.

Tribal Notes

Tribe Dalbergieae

Lima (1989) analyzed the morphological characters of fruits, seeds and seedlings of the tribe and his characters and illustrations were used as a much appreciated source of accurate data. He also discussed the phylogeny of the tribe. Sousa and Sousa (1981) provided data to support their conclusion that the New World Lonchocarpinae be considered for tribal status: A segregate of the Dalbergieae. Hauman (1954) provided data on the Dalbergieae of Central Africa, and Lock (1989) listed the Dalbergieae for all of Africa. Thothathri (1986) reviewed the taxonomic status and systematic position of Asiatic Dalbergieae, and monographed tribe Dalbergieae for the Indian subcontinent (Thothathri, 1987). Morphological (Lima 1989) and molecular (Doyle et al. 1997) evidence has indicated that tribe Dalbergieae is polyphyletic.