Monographs Details: Calliandra pityophila Barneby
Authors:Rupert C. Barneby
Authority: 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.
Description:Species Description - Slender microphyllidious shrublets to 5 dm tall with erect terete lenticellate stems, appearing glabrous but the young branchlets, lf-axes, and peduncles thinly minutely appressed-pilosulous, the moderately bicolored lfts brown-olivaceous when dry, dull and glabrous on both faces, a little paler beneath, thinly appressed-ciliolate, the few-flowered capitula arising singly or geminate on subfiliform peduncle from lowest nodes of shortly caulescent brachyblasts; phyllotaxy distichous. Stipules firm, narrowly triangular or subulate ±1-2.4 mm, evenulose dorsally, tardily deciduous. Lf-formula i/11-19; lf-stks 2.5-7 x 0.3-0.6 mm; pinna-rachises 2-4 cm, the longer interfoliolar segments 1.4-3.3 mm; lft-pulvinules 0.2-0.4 x 0.30.5 mm, not wrinkled; lfts a little decrescent at each end of rachis, otherwise subequiform, the blades oblong-elliptic from semicordate base, obtuse apiculate, those near mid-rachis 4.5-8.2 x 1.5-2.7 mm, 2.4-3.1 times as long as wide; venation faint, the midrib displaced to divide blade ±1:1.5-2, finely 2-3- branched on each side, the inner of 2(-3) posterior primary nerves scarcely attaining mid-blade. Peduncles ±2-3 cm, ebracteate; capitula 4-9-fld, the receptacle 0.5—1 mm diam, one terminal fl sometimes broader than the rest but hardly longer and its androecium not differentiated; pedicels 0.7-1 x 0.4 mm; perianth 5- merous, almost glabrous; calyx of peripheral fls 1-1.15 x 1.3 mm, weakly 5-nerved, the deltate-ovate teeth 0.2-0.3 mm; corolla 6 mm, the ovate lobes ±1.4 mm (one pair sometimes united almost to tip); androecium 14—15-merous, red throughout, 26 mm, the tube ±5 mm, the stemonozone ±1 mm; intrastaminal nectary 0.6 mm; ovary substipitate, glabrous at anthesis. Pod unknown.

Distribution and Ecology - In pine forest near 1500 m, known only by the type-collection from the n. slope of Sa. Madre del Sur near 17°40'N, 10°38'W in Guerrero, Mexico. — Fl. XII-II(-?).

Relationships and variation - This is one of several, as yet poorly known calliandras of low slender growth found in pine forest of tropical Mexico, but is the only one of them with only one pair of pinnae per leaf. It has no obvious close kindred and is arbitrarily compared in the diagnosis with C. colimae, which differs in leaf-formula.

Distribution:Guerrero Mexico North America|