Calliandra Species Pages


Calliandra trinervia


Rupert C. Barneby

68.  Calliandra trinervia Bentham, London J. Bot. 3: 94. 1844. — Typus infra sub var. trinervia indicatur.

Macrophyll arborescent shrubs and trees commonly 10 m or less but in far western Amazonia attaining 30(-35) m x 2 dm dbh, with gray-pallescent trunks and annotinous branches, commonly glabrous throughout except for thinly minutely puberulent corolla but occasionally the young stems and lf-axes thinly pilosulous or (var. pilosifolia) densely setose- pilose, the ample, thinly chartaceous lfts bicolored, lustrous dark green (when dry brunnescent) above, paler beneath, the epiphyllum sometimes puberulent along primary nerves, rarely pilose along nerves beneath and ciliate, the capitula borne either a) singly (paired) at 1-2, stipulate but efoliate nodes of small thatched brachyblasts axillary to a contemporary or lately fallen lf, or b) in var. paniculans at nodes of extended axillary and terminal pseudoracemes; phyllotaxy distichous. Stipules most often bluntly deltate or broadly triangular 0.6-4 x 1-3.5 mm, less often lanceolate and 3-6 mm or (var. pilosifolia) attaining 10(-22) x 1-2 mm, striate at least when young but sometimes thickened in age, becoming pallid and externally nerveless, persistent. Lf-formula i/1, 1½, 2, the proximal posterior lfts, when present, ½ or as big as the further pair and inserted well below mid-rachis; lf-stk of larger primary lvs (0.3-)0.5-4(-4.5) cm, at middle 0.6-1.7 mm diam, distended and bicupular at apex, the ventral groove wide and shallow; pinna-rachises of larger lvs (1-)1.4—4.5 cm; lft-pulvinules 1.5—3(—3.4) x 0.8-1.6 mm, coarsely cross-wrinkled; blade of lfts inequilaterally or subdimidiately elliptic or ovate from cuneate or broadly cuneate base, either shortly bluntly or attenuately acuminate, the distal pair in larger lvs 5.5—16(—17) x (2-)2.5-6(-7) cm, ±1.9-3.1(-3.7) times as long as wide; venation palmate-pinnate, of 3-4 primary nerves from pulvinule, the gently incurved midrib displaced to divide blade 1:1.8-2.5, pinnately ±7-10-branched on both sides, the strong inner posterior primary nerve incurved-ascending through at least ? length of blade and often further, the outer l(-2) much shorter, all these usually prominulous on both faces, especially in young lvs, the tertiary and reticular venulation either sharply defined on both faces of blade or immersed on upper one. Peduncles (0.35-) 10-40 mm, minutely bracteate either above or below middle (exceptionally ebracteate or the bract deciduous); capitula 9-27-fld, the floral receptacle sub-spherical or claviform 1-3 mm; bracts ±0.5-1 mm, incurved, persistent; fls (of most capitula, perhaps potentially of all) heteromorphic, many peripheral ones staminate, few bisexual, the perianth of 1-3 central fls scarcely longer than that of peripheral ones but often stouter and its androecial tube always much longer, distended distally into a pallid trumpet; perianth of all fls either 4- or 5-merous, thin-textured, the striate calyx usually glabrous, the corolla-tube commonly puberulent or appressed-strigulose but sometimes glabrous, rarely (var. peruicola) papillate: PERIPHERAL FLS: pedicel often not or scarcely differentiated externally except by discoloration, visible in cross-section, or distinct externally and to 0.7 mm; calyx either campanulate, or deeply campanulate, or cylindric to cylindric infundibuliform, prevalently 0.8-3.7 x 0.6-1.4(-l.8), in var. carbonaria to 2.7 mm, the broad obtuse teeth 0.15-0.4 mm (one sinus may be more deeply split), in rare var. stenocylix (q.v.) longer and longer-toothed; corolla (5—)5.5—12.5 (in vars. pilosifolia and stenocylix potentially to 14) mm, the ovate, sometimes unequal lobes (1-)1.2-2.8 mm; androecium 12-28(-32)-merous, (21-)25-52 mm, the stemonozone ±0.8-1.2 mm, the pallid tube (5-)7-18(-22) mm, as long as corolla or far exserted, the tassel pink or carmine, exceptionally white; ovary at anthesis glabrous; CENTRAL FL(S): like the peripheral ones but the androecial tube 15-25 mm, expanded to 2-4.5 mm diam at orifice; a tub-shaped intrastaminal nectary present but no ovary. Pods purplish-brown or fuscous, glabrous or exceptionally ciliate, in profile (7-)8-25 x 0.9-2 cm, the sutural ribs (2.5-)3.5-7 mm wide in dorsal view, the plane lignescent valves usually weakly venulose, the obliquely transverse nerves immersed or only slightly obtusely elevated; seeds compressed-lentiform, in broad view oblong or oblong-elliptic 12-22 x (6-)7-12 mm, the smooth thin testa becoming papery, castaneous or light brown, lustrous, pleurogram in S. America 0, in N. American var. arborea present.

Calliandra trinervia, as defined in the foregoing description, is the one common Amazonian species of the genus characterized by amply 4-, 6- or 8-foliolate leaves, palmate-pinnate venation of leaflets, bicolored filaments, and weakly venulose pod. Sympatric or closely vicariant relatives are: C. bombycina, ecologically modified in seasonally dry woodland of the Huallaga Valley in Peru and morphologically differentiated by striate corolla and more numerous stamens, red throughout; C. jariensis, local in Para, and C. harrisii, of the Andean foothills in Bolivia and of extra-Amazonian Brazil, together characterized by pinnate venation of the leaflets; C. glyphoxylon of the west slope of the Andes in Ecuador, which see for differential characters; and C. hymenaeodes, of Atlantic lowlands in the Guianas, deceptively similar except for simply pinnate, not bipinnate, leaves. Outside Amazonia the species is represented further by scarcely differentiated varieties localized in northwestern Peru, inter-Andean southern Colombia, and tropical North America, as described in the following pages.

References: [Article] Barneby, Rupert C. 1998. Silk tree, guanacaste, monkey's earring: A generic system for the synandrous Mimosaceae of the Americas. Part III. Calliandra. Mem. New York Bot. Gard. 74: 1-223.