Trees 2-8 (-10, once reported 20) m tall with habit, indumentum and bicolored androecia of Cc. surinamensis and riparia, variable in size and number of lfts, these lustrous dark green above, paler duller beneath, facially glabrous or rarely pilosulous, randomly ciliolate, the peduncles arising singly or less often geminate from bracteate axils of either loosely or densely thatched brachyblasts; phyllotaxy distichous. Stipules subtending primary lvs of long-shoots lanceolate, lance-attenuate or narrowly triangular 2.5-9 x 0.1-2.1 mm, when young striately 7-15- nerved, becoming dry and fragile, those of brachyblasts similar but a little shorter. Lf-formula i/(12—) 13-36; petioles 2-10(-12) x 0.35-1.2(-l.4) mm; pinna-rachises of primary lvs 4-10 cm, of brachyblast lvs often shorter and in foliose saplings reaching 12 cm, the longer interfoliolar segments 1.3-6.5 mm; lft- pulvinules 0.1-0.4 x 0.35-0.8(-0.9) mm; lft-blades usually longest at mid-rachis but only a little shorter at base and apex, the terminal pair no (scarcely) longer than the penultimate, all in outline varying from linear to oblong from semicordate or angulately auriculate base, obtuse mucronulate or apiculate, straight or gently incurved beyond middle, the longer ones (6—)7—18 x 1.4—6 mm, 2.2-5.6(-6.4) times as long as wide; venation of narrower lfts almost simply pinnate, of broader lfts clearly palmate-pinnate, the midrib only slightly excentric, the inner posteRíor primary nerve incurved-ascending to or beyond mid-blade of broader lfts but weak and short in narrow ones, the secondary and reticular venules all finely sharply prominulous on both faces. Peduncles (2-)5—12 mm, mostly bracteate below middle; capitula 16—28-fld, the receptacle 1.5-4 mm; bracts subulate 0.6-2.2 mm, 1-3- nerved, persistent; pedicels (sometimes scarcely differentiated externally) 0.25-0.55(-0.7) x (0.25-)0.3- 0.9 mm; perianth either 4- or 5-merous, commonly glabrous but sometimes minutely puberulent or strigulose, the calyx striate, the corolla not so; flowers within the capitulum either subhomomorphic or strongly heteromorphic, the perianths subequal in all but the androecial tube of the peripheral ones, sometimes of all, as long as or up to 4.5 mm longer than corolla, that of 1-3 subterminal fls cylindric 20-32 mm, expanded at orifice to 4-5 mm diam; calyx campanulate 1.2-2.2(-2.7) x 0.9-1.3(-l.5) mm, the teeth 0.1-0.4 mm; corolla (3.8-)4.2-6.6(-7.5) mm, the lobes 0.9-1.8 mm; androecium 25-42 mm, (9-)10- 15-merous, pallid proximally, the tassel carmine; ovary at anthesis glabrous, becoming puberulent after fertilization. Pods stiffly erect from the plagiotropic branches, in profile 7-11 x 0.9-1.35 cm, massively woody and inflexible in texture, brown nigrescent, the longitudinally ribbed sutures 3.5-5 mm wide in external view, 1.5-2 mm thick at the plane of dehiscence, the deeply recessed, coarsely obliquely venulose valves 2-5 mm wide, often narrower than either suture, the whole sordid- or brown-puberulent in youth but sometimes glabrate at maturity; seeds fawn, fuscous-speckled, in broad view 8-9.6 x 5-6.2 mm, the smooth testa finely pleurogrammic.