C. gardneri sensu Bentham, 1875: 550; 1876: 421.

Microphyllidious, functionally herbaceous subshrub from oblique woody rootstock, the simple ascending stems 2-3 dm bearing ±3-5 lvs and 1-2, proportionately large, axillary capitula, the whole plant glabrous except for traces of puberulence on lf-axes and minutely strigulose perianth, the firm plane lfts bicolored, dark olivaceous sublustrous above, pale dull green beneath, the furthest (or only) peduncle often appearing terminal and continuous with primary cauline axis due to abrupt inhibition of terminal meristem beyond the furthest lf. Stipules lanceolate 2-5 x 0.7-2 mm, weakly several-nerved, becoming dry fragile, but only very tardily deciduous. Lf-formula (ii—)iii—v/( 14—) 18-29; lf-stks of longer lvs 5-9 cm, the petiole 8-28 mm, the longer interpinnal segments 13-24 mm, the rachis dilated into a cupule under each pinna, the ventral groove continuous but constricted at insertion of pinnae; lft-pulvinules 0.4-0.7 mm; lfts subequilong except at each end of pinna-rachis, the blade narrowly oblong or lance-oblong from obtusangulate base, at apex either rounded or depressed-deltate, those near mid-rachis (9—)10—15 x 3.3-4.7 mm, 2.7-3.6 times as long as wide; venation palmate-pinnate, the straight midrib forwardly displaced to divide blade 1:1.8-3 and giving rise on its posterior side, near and beyond mid-blade, to 3-6 secondary nerves ascending to anastomosis well within the margin, the inner posterior primary nerve incurved-ascending ± to midblade, the outer 1—2 much shorter, tertiary venulation 0 or faint, the whole venation prominulous on hypophyllum, scarcely raised above. Peduncles solitary or exceptionally geminate, erect stout 6-12 cm, 1- bracteate below middle; capitula densely 5-11-fld, the ascending fls homomorphic or almost so (the terminal fl sometimes stouter than the rest but neither longer nor otherwise modified), the clavate receptacle 2-4 mm diam; floral bracts 0 or reduced to vestigial caducous scales; pedicels claviform or stoutly turbinate 1-2.5 x 1.4-2 mm; perianth pallid pink- tipped, the calyx either puberulent or glabrous ciliolate, faintly nerved, the corolla minutely strigulose; calyx campanulate 3-5 x 3-4 mm, the broad obtuse teeth 1.4-2.2 mm; corolla 13-17 mm, the broadly ovate lobes 4.5-7.5 mm; androecium 46-92-merous, 6-7.4 cm, the inwardly thickened stemonozone 3.5-4 mm, the tube to 12 mm, the tassel carmine proximally, whitish distally; no intrastaminal disc; ovary subsessile, at anthesis glabrous. Pods 1-2 per capitulum, in profile linear-oblanceolate 9.5-14 x 1.2-1.6 cm, the sutural ribs in dorsal view 3-4 mm wide, the recessed valves castaneous sublustrous, transversely venulose, minutely puberulent overall; seeds in broad profile obovate-elliptic 10.5-14 x 6-8 mm, the testa light brown, smooth but dull, the pleurogram lacking.

In sandy and rocky places in campo cerrado, 600-1000 m, localized on the w. slope of Sa. Geral de Goiás, on right effluents of upper rio Tocantins, between 11°S and 13°20'S, in e.-centr. state of Goiás. — Map 16. — Fl. I-III.

Calliandra gardneri is notable for low stature, few cauline leaves, a pseudoterminal capitulum (not truly terminal, as in C. brevicaulis), large flowers, filament- tassel white distally but pink proximally (the reverse of the usual pattern) and seed-coat lacking pleurogram.