Slender microphyllidious shrubs of unknown potential stature with terete defoliate annotinous and older stem, the young stems, lf-axes, and peduncles gray-pilosulous with spreading or incurved-ascending grayish hairs to ±0.5-0.7 mm, the lvs bicolored, the firm, contiguous or imbricate, facially glabrous but finely ciliate or granular-ciliolate lfts lustrous dark brown above, paler dull beneath, the capitula arising singly from efoliate axils of either short and thatched or ± extended brachyblasts; phyllotaxy distichous. Stipules firm, lanceolate or narrowly triangular-acuminate ±1.4-5 x 1-1.5 mm, dorsally not or indistinctly venulose, puberulent but glabrate in age, persistent. Lf- formula iv-viii/32-40; lf-stk of longer lvs 3-7 cm, the petiole including pulvinus 5-11 mm, at middle 0.7-1 mm diam, the longer interpinnal segments 5—10(—12) mm, the shallow sulcus bridged; pinnae a little, sometimes randomly, accrescent distally, the rachis of further ones 3-5 cm, the longer interfoliolar segments 0.45-1 mm; lft-pulvinules ±0.2 x 0.3 mm, scarcely wrinkled; lfts subequilong or gradually decrescent from near mid-rachis upward, the blades linear or linear-oblong from obtusangulate base, obtuse or deltately subacute, the longer ones 3.6-5 x 0.9-1.4 mm, (3.2-)3.5-4.8 times as long as wide; midrib straight, finely prominulous only dorsally, displaced to divide blade ±1:2, weakly 2-3-branched distally, the posterior primary nerve very short or imperceptible. Peduncles 1.5-4 cm, bracteate above middle, the bract lance-elliptic 1.5-2 mm; capitula incipiently recemiform ±15—20-fld, the ellipsoid-claviform pitted receptacle 2-3 x 1.5-2 mm; floral bracts minute fugacious; pedicels 0.3-1 x 0.5-0.9 mm, perianth submembranous 5-merous, the calyx thinly puberulent, brownish, faintly 5-nerved (not striate), the corolla densely sub-appressed-silky, externally nerveless; calyx campanulate ±2 x 2.5 mm, the deltate teeth 0.5-0.7 mm; corolla 6.5-7.5 mm, the erect ovate-lanceolate lobes 2.2-3.8 mm; androecium (one exactly observed) 28-merous, 2.5 cm, the stemonozone 1.3-1.5 mm, the tube 1.6-3.1 mm, the tassel red. Pods 3.5-9.5 cm, in broad profile 6-8 mm wide, minutely erect-pilosulous overall, the ribs in dorsal view 1.3-2 mm wide, the recessed valves openly transverse-venulose; seeds not seen.

In campo cerrado at elevations not recorded, known from two stations in hill country between 4°S and 5°S in n. Piauí and from Chapada da Ibiapaba in adj. n.-w. Ceará, Brazil. — Map 20. — Fl. VI-X, or following rains.

Calliandra fernandesii resembles C. ulei in habit and leaf-formula, but differs in longer leaf-stalks, obscurely pedicellate flowers, silvery-silky perianth,  deltate calyx-teeth, and relatively short perianth-tassel red throughout. This distinctive species is named in honor of Professor Afrânio Gomes Fernandes of Universidade Federal do Ceará, Fortaleza, to whom The New York Botanical Garden is indebted for gifts of rare and critical Leguminosae from northeastern Brazil.