Zygia cataractae

Inga ramiflora G. Don, Gen. Hist. 2: 392. 1832. — "Native of Guayaquil. Mimosa ramiflora, Ruiz et Pav[ón] in herb.  Lamb[ert.]." — Holotype to be sought at OXF. — Equated by Bentham (1875: 595) with Pithecolobium glomeratum Bentham quod = Z. cataractae L. Rico. — Non I. ramiflora Steudel, 1843.

Pithecolobium cauliflorum fma. niveum Lindman, Bih. Kongl. Svenska Vetensk.-Acad. Handl. 24(3): 7: 56. 1898. — "Bras[il]: Matto Grosso, S Cruz da Barra do Rio dos Bugres, in ripa silvatica fluvii Alto-Paraguay [±15°S, 57°10'W], mens. Apr. [1894] florens (A. 3193)." — Holotypus, S (3 sheets)!.

Pithecellobium divaricatum Bentham, London. J. Bot. 3: 213. 1844. — "Brazil, [L. Riedel, commun.] Langsdorff." — Holotypus, received by Bentham from Petrograd under the unpublished name Inga divaricata Bongard, K (hb. Bentham., annot. Sandwith)! = NY Neg. 2025; isotypi, NY (3 sheets, one labeled with location and number, one without locality but numbered Riedel 2195, the other without number, from Borba, collected 18 Jul 1828)!. — Zygia divaricata (Bentham) Pittier, Trab. Mus. Com. Venezuela 2: 69 = Arb. Arbust. Legum. 1: 39. 1927, lacking full bibliographic citation.

Calliandra schwackeana Taubert, Flora 75: 69. 1892. — "Habitat in Brasilia boreali prope Manáos: Schwacke n. 111,291; Glaziou 13793." — Syntypi, †B, one (Glaziou 13793) = F. Neg. 1256!.

Pithecellobium divaricatum sensu Hoc, Darwiniana 23: 538, fig. 4. 1981; Barbosa, 1991: 305, fig. 10.

P. glomeratum sensu Barbosa, 1991: 311, the name illegitimate in this context, because synonymized with P. cataractae, based on an earlier epithet.

Macrophyllidious arborescent shrubs and slender trees, at anthesis (1.5—)2—12(—15, once recorded, Little 8415, NY, as 25) m tall, commonly several-stemmed from base, the trunk(s) attaining l-1.5(-"4") dm dbh, the annotinous and older branches pallid, gray or yellowish, the nascent branchlets brown-strigulose, the lf-axes sometimes and the inflorescence-axes almost always minutely strigulose but the dull olivaceous, moderately bicolored, stiffly chartaceous lfts glabrous, the inflorescence composed of capitula or capituliform spikes of sessile fls arising, either solitary or fasciculate, either directly from knots on trunk and annotinous or older branches or exceptionally from older lf-axils, or rarely assembled into condensed few-capitulate efoliate pseudoracemes. Stipules deltate or triangular (0.5-)0.7-2.3 mm, nerveless dorsally, usually caducous, absent from fruiting specimens. Lf-formula usually i/l½, rarely (and not in all lvs of an individual) i/2, the distal pair about twice as large as the l(-2) proximal ones; lf-stks 2-11 (-13) x 1.3-2.5 mm; nectary at tip of lf-stk sessile, round (0.8—) 1.1-2.7 mm diam, either shallow-cupular or low-convex within a cupular margin, often bug-eaten, a similar but smaller nectary at tip of each pinna; pinna-rachises (0.7-)1.5- 5.5 cm, the posterior lft (or pair of lfts) inserted well below middle, often close to pulvinus; lft-pulvinules in dorsal view 2-5 mm; lft-blades elliptic to ovate- or lance-elliptic from more or less inequilateral, either cuneate or semicordate base, shortly acuminate and at very tip either deltately acute or obtuse, the distal pair of larger lvs (6-)8-18(-20) x (2.6-)3-6.5(-8) cm, (2-)2.1-3.9 (-4.4) times as long as wide; venation primarily pinnate, the straight or gently incurved, sub-centric midrib giving rise on each side to 6-10 major (and indefinite intercalary) secondary nerves widely incurved-ascending and brochidodrome well within the plane margin, and these to tertiary and reticular venulation usually finely prominulous on both faces. Peduncles 1—9(—11) mm, mostly arising directly from the cauline knot, a pseudoracemose axis up to 2 cm sometimes developing, its early nodes subtended by a rudimentary lf-stk with nectary; capitula (5-)8-25-fld, the receptacle 1-5 mm; bracts <1 mm, persistent; perianth glabrous or puberulent, the calyx weakly 5-nerved, the corolla-tube delicately but prominulously ±15-nerved, the lobes almost nerveless; calyx shallow-cupular to deeply campanulate, (0.45-)0.6-2.6 (-3.1) x 0.7-1.5 mm, 0.5-2.5 times as long as wide, the teeth minute, not over 0.2 mm, the orifice often merely crenulate; corolla subcylindric (4.5-)5.5-9 (-10) mm, the erect, often unequal lobes 0.5-1.8 mm; androecium (24-)28-55(-62)-merous 15-22 mm, the tube 7—12(—12.5) mm, exserted from corolla 0.5-4 mm, usually white throughout, but the tassel sometimes pink; intrastaminal disc 0.3-0.8 mm tall; ovary subsessile, linear-elliptic, glabrous, the stigma scarcely dilated, ±0.1-0.2 mm diam. Pods 1-3 per capitulum, sessile or almost so, in profile broad-linear, variably recurved, either weakly falcate or bent into a circle, when well fertilized 8-28 x 1.4-2.6 cm, 8-14-seeded, strongly compressed, the coriaceous, glabrous or exceptionally finely puberulent valves at first green and plane except for a depressed papilla over each seed, becoming brown and low-convex over seeds, framed by longitudinally sulcate sutures; dehiscence tardy, through the ventral suture, the valves narrowly gaping to release the seeds; seeds transverse, compressed but plump, in broad view obtusely rhombic or oblong-elliptic, ±15-20 x 13-16 mm, the papery testa dull brown, lacking pleurogram.

In riparian woodland subject to flooding, on low riverbanks, in gallery forest, mostly below 250 m but attaining 475 m in Venezuelan Guayana, interruptedly widespread over the Amazon basin, the S half of the Orinoco basin, and the Guianas, between 9°N and 13°30'S latitude, thence rarely S in Brazil to the headwaters of Río Paranaiba in the Triângulo Mineiro; reappearing disjunctly, in a form with relatively small lvs, along the lower Paraná and adj. Paraguai Rivers in  lat. 27°-28°S, in NE Argentina (SW Misiones, N Corrientes, NE Santa Fe) and contiguous Paraguay; one disjunct record from Pacific Ecuador (Milagro, Guayas). — Map 32. — Fl. nearly throughout the year, most profusely VI-X. — Cimbra-potro (Orinoco valley); clavellino, guama de rana (Venezuelan Gua- yana); alikuyu (Guyana); bushillca, yacushapam (Peru); ingá branca (N Amazonian Brazil); guará-peré (Argentina, applied also to sympatric Z. morongii).