Shrubs 3 m with slender terete branchlets, the new stems and lf-stks densely gray-puberulent with incurved hairs to 0.4 mm but the relatively ample, venulose lfts facially (sub)glabrous ciliolate, dark brown- olivaceous sublustrous above, dull pale brown beneath, the capitula of glabrous fls borne singly on loosely thatched lateral brachyblasts; phyllotaxy distichous. Stipules subtending primary lvs linear-lanceolate ±2-4 x 0.4—0.6 mm, weakly ±5-nerved, becoming papery, those of thatched brachyblasts broader and shorter. Lf- formula i/4—6; lf-stks ±5-8 mm, at middle 0.5-0.8 mm diam; pinna-rachises (1.5-)2-4.5 cm, the narrow ventral groove interrupted at insertion of lfts, the longer interfoliolar segments 5-8 mm; lft-pulvinules 0.4—0.5 x 0.6-0.8 mm, indistinctly cross-wrinkled; lfts distally accrescent, the blades oblong-, ovate- or incipiently rhombic-elliptic from broadly obtusely semicordate base, abruptly deltate-apiculate at rounded or shallowly emarginate apex, the penultimate pair 14—19 x 4.5-8 mm, 2.3-3 times as long as wide, the terminal pair often somewhat longer; venation palmate-pinnate, the midrib scarcely excentric, straight or almost so, 4—6-branched on anteRíor side, the inner of 3 posterior primary nerves incurved-ascending beyond mid-blade, the outer ones much shorter, all these together with tertiary venules pallid and slenderly prominulous on both faces. Peduncles 2-2.5 cm, ebracteate; capitula ±12- 16-fld, the receptacle 1-1.5 mm diam; bracts ovate or subulate 0.4—0.8 mm, microciliolate, persistent; fls homomorphic, the 5-merous perianth glabrous except for microscopic ciliola, the calyx weakly ±15-striate, the corolla not so; pedicels 0.2-0.6 x 0.3-0.5 mm, essentially 0 in furthest fls; calyx campanulate 1.6-2 x 1-1.6 mm, the depressed-deltate teeth 0.2-0.3 mm; corolla 6.6-7 mm, the ovate, broadly obtuse lobes to 2 mm; androecium 16-merous, 16-17.5 mm, the tube ±5 mm, the stemonozone 1.1 mm, the tassel (not seen fresh) apparently red; ovary at anthesis glabrous; intrastaminal nectary (of 1 bisexual fl dissected) 0.6 mm tall. Pod not known.

In a wet barranca, probably in the oak-pine belt near or above 1100 m, known only from the type-locality at 15°53'N, 100°28'W in district of Temascal-tepec, state of México. — Fl. VI, and probably in other months. — Cabello de angel, a generic name for red-stamened Calliandra in Mexico.

The type-collection of C. hintonii has now lain for sixty years among unidentified calliandras, unmatched by new material and anonymous. It represents an undescribed species of uncertain affinity, characterized by the low leaf-formula of i/4-6, leaflets of moderate size, and a red 16-merous androecium. In technical characters it approaches the Guatemalan C. carcerea, but has fewer leaflets per pinna.