54.  Calliandra duckei Barneby, sp. nov., hucusque cum C. blanchetii, cui foliorum formula ac capitulis unbelliformibus accedit, confusa, sed ab ea imprimis florum periphericorum perianthio subduplo minori, calyce ±1.4 (nec 3-4.3) mm et corolla 4 (nec 6.5-8) mm longis necnon flosculi terminalis tubo androeciali longe exserto diversa. — BRAZIL. Pernambuco: Russinha, 4 Feb 1933 (fl), D. Bento Pickel 3213. — Holotypus, GH.

C. blanchetii sensu Ducke, 1953: 51; non Bentham.

Stiffly awkwardly branched, microphyll, drought- deciduous shrubs or treelets of unknown stature, the new stems, lf-axes, and units of inflorescence thinly pilosulous with extremely fine white ascending hairs to ±0.5 mm, the lvs bicolored, the facially glabrous ciliolate lfts dull olivaceous above, paler beneath, the umbelliform capitula borne single in the first efoliate axil of brachyblasts axillary to primary lvs. Stipules of primary lvs (few seen) lance-attenuate ±3-4 mm, striately 3-5-nerved, becoming dry fragile, those of brachyblasts similar but smaller, closely imbricate. Lf-formula i/20-24; petioles 3-4 x 0.2-0.4 mm; rachis of pinnae ±1.5-2 cm, the longer interfoliolar segments 0.6-0.8 mm; lft-pulvinules 0.2 mm; lfts abruptly smaller at each end of rachis, otherwise subequilong, the blades linear-oblong from bluntly auriculate base, obtuse, nearly straight, the longer ones ±3.6-4 x 0.9-1.1 mm; venation pinnate, the midrib only a trifle displaced from mid-blade, divaricately 5-6-branched on either side. Peduncles 5-18 mm, 1-bracteate well above middle, the papery bract <1.5 mm, the receptacle 1-1.5 mm; floral bracts ±1 mm, deciduous; fls dimorphic, the peripheral ones pedicellate, the central one sessile or nearly so, larger, and its androecium trumpet-shaped, its tube far-exserted; perianth of all fls 5-merous, thinly finely pilosulous; PERIPHERAL FLS: pedicel 1-2.3 x 0.20.3 mm; calyx turbinate-campanulate ±1.4 mm, the tube bluntly 5-angulate, the obtuse teeth 0.25 mm; corolla 4 mm, the ovate lobes 1.7-2 mm; androecium 16-18-merous, ±17 mm, the stemonozone <1 mm, the tube ±2.5 mm; intrastaminal disc 0; TERMINAL FL: calyx broadly campanulate ±2.5 x 2.5 mm; corolla 7.5 mm, the lobes 2.2 mm; androecium 18-merous, ±20 mm, the tube 14 mm, the intrastaminal disc ±0.6 mm; ovary subsessile, distally pilosulous. Pod unknown.

In unreported habitat, but to be expected in seasonally dry scrub thickets at low elevations, known at present only from the type-locality at 8°09'S, 35°30'W in w. Pernambuco, Brazil. — Fl. I—II(—?).

Calliandra duckei has much in common with C. blanchetii and could easily be mistaken for it in absence of authentic material of the latter, which Ducke may well not have seen. It differs from C. blanchetii primarily in much shorter peripheral flowers; see Latin diagnosis for measurements. Calliandra brevipes, which ranges from Salvador, Bahia, far southward, has similar leaves, but broad short stipules, truly capitate, not umbelliform units of inflorescence, and prominently striate-venulose calyx.