Zygia ampla

  • Title

    Zygia ampla

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Zygia ampla (Benth.) Pittier

  • Description

    41. Zygia ampla  (Bentham) Pittier, 3rd Conf. Interam. Agric. Caracas 359. 1945. Pithecolobium amplum Bentham in Martius, Fl. Bras. 15(2): 451. 1876. — "Habitat in silvis ‘Gapo’prope Manaos, prov. do Alto Amazonas: Spruce n. 1852." — Holotypus, K (hb. Bentham.)!. = NY Neg. 2028; isotypus, †B = F Neg. 1179!.

    Pithecolobium brevispicatum Ducke, Arch. Jard. Bot. Rio de Janeiro 3: 69. 1922. — ". . . in civitate Pará in silva riparia fluminis Trombetas prope cataractam Porteira l[egit] A. Ducke 29-11-1907 n. 4.949, fluminis Xingú prope Altamira l[egit] A. Ducke 21-8-1919 H[erb.] J[ard.] B[ot.] R[io de Janeiro] n. 10.202, fluminis Guamá superioris prope São José (supra Ourem) l[egit] R. Siqueira 12-12-1903 n. 4.065 . . . [also cited are J. Huber 8829 and Ducke in MG 685]." — Syntypi, Ducke 10202 (RB), Huber 8829 (MG). Pithecellobium amplum sensu Barbosa, 1991: 319.

    Slender macrophyllidious cauliflorous trees (3-) 4-10 m with trunk attaining 1.5 dm dbh, the young stems, lf-axes, and inflorescence densely sordid-puberulent but the lfts commonly so only along principle nerves (the intervenium rarely also remotely  puberulent), the inflorescence when fully expanded a short, simple or few-branched pseudoraceme of capituliform spikes, these short to laxly elongate. Stipules (few seen) deltate-triangular 1-1.5 (-?) mm, not striate, caducous. Lf-formula i/3½-5½(-6½), each lf 14- 22(-26)-foliolate; lf-stks 3-10 x 1.6-5 mm; nectary at tip of petiole sessile, shallowly cupular or almost plane, 1.6-3 mm diam, similar but smaller nectaries between some distal or between all lft-pairs; pinnae divergent almost at right angles from the petiole, thence either straight or incurved, often of unequal length, the longer one 11-21 (-28) cm, the longer interfoliolar segments 3-6.5(-9) cm; pulvinules 2-5 x 0.8-2.2 mm; lfts usually accrescent distally, narrowly to broadly ovate-elliptic from inequilaterally broad-cuneate or shallowly semicordate base, shortly acuminate, the distal pair (8-)9-20(-27) x 3-9.5 cm, 2.2-3.4(-3.7) times as long as wide; venation prominulous only on lower face, the subcentric, straight or nearly straight midrib giving rise on each side to 2-5 major incurved-ascending (and indefinite weak intercalary) secondary nerves, the first or both first and second of these on posterior side (in proportionately ample lfts on both sides) of midrib produced well beyond midblade, the tertiary and reticular venulation faint or ill-defined. Inflorescence more or less compound but very variable in extension of axes, the primary one 1.5-5 cm, sometimes scarcely developed, the peduncles 1-5 mm, all or most of them subtended by a rudimentary lf-stk with nectary; capitula 8-20-fld, the sessile fls either contiguous or well separated, the floral axis becoming 1.5-7 mm; bracts ovate acute, <1 mm, persistent; perianth brown-puberulent overall, the calyx faintly 5-nerved, the corolla-tube finely striate; calyx campanulate, sometimes deeply so, 0.9-1.9(-2.4) x 0.7-1.3 mm, the teeth at most 0.2 mm, often subobsolete; corolla tubular, only slightly dilated at the limb, 4.5-6.7(-8) mm, the erect lobes 0.6-1.3 mm; androecium 26-38(-46)-merous, 16-20(-23) mm, the tube 7—10(—12) mm, exserted 1-2.8 mm, the tassel pink or crimson; intrastaminal disc 0.3-0.45 mm; ovary glabrous, tapering into the style. Pods (few seen) sessile, broad-linear, straight or gently retrofalcate, 8-18 x 1.8-2.8 cm, plano-compressed, to 12-seeded, the stiffly leathery, dark brown, low-venulose valves framed by shallowly undulate or nearly straight sutures 1.5-3 mm wide, at first densely puberulent, glabrescent; dehiscence and seeds unknown.

    In annually flooded forest, mostly below 200 m but ascending to 600 m in Guyana, scattered through centr. and E Amazonia between ±3°N and 5°S, in Brazil from the lower Japurá in Amazonas E to the Amazon delta and N Maranhão, N through Roraima just into Guyana (Kanuku Mts., Kuyuwini River), and known from one station on the sources of the Tocantins near 14°50'S in Goiás. — Map 31. — Fl. VIII— XII. — Jarendeua de sapo.