Pithecellobium keyense

P. keyense sensu Isely, 1973: 114, map 40 (penins. Florida); Correll & Correll, 1982: 679, fig. 281; Bisse, 1988: 223.

Macrophyllidious unarmed shrubs and trees (1.5-) 2-5.5(-7) m with often scabrously lenticellate branchlets, either glabrous throughout or glabrous except for thinly puberulent peduncles and minutely silky-strigulose perianth, the stiffly papery lvs always hairless, either concolorous or a little paler beneath, olivaceous mostly drying brown, the capitula of either whitish or reddish-, white-, sordid-, or roseate- stamened fls borne solitary along the axis of efoliate (depauperately foliate) pseudoracemes arising from lf-axils of both coeval and annotinous branchlets, either immersed in foliage or shortly exserted. Stipules either triangular-subulate, appressed to stem and <1 mm, a little thickened but never spinescent, or vestigial, or at some or most nodes obsolete. Lf-formula either i/1 or i/1-2, either all or most lvs exactly 4-foliolate, often some (never all) 6- or 8-foliolate, one or both pinnae 4-foliolate; petioles accrescent upward through the annual stem growth, 1.5—17(—20) mm, the early ones (sometimes all) very short, all widely shallowly sulcate and 0.8-2.5 mm wide distally, most or all shorter than or barely equaling the pinna- rachises; nectary at tip of lf-stks sessile or nearly so, cupular thick-rimmed, 0.7-1.5 mm diam, a similar, slightly smaller nectary at tip of each pinna-rachis; rachises of pinnae either of equal length or one longer, both as long as or in majority of lvs longer than the petiole, (0.7-)l-4(-6) cm; lfts equilong or the proximal pair smaller, all obovate, or oblanceolate, or oblance-elliptic from semicordate base, either broadly obtuse, or truncate-emarginate, or obtuse apiculate, the larger ones (3-)3.5-8.5(-9) x (1.3-) 1.5-4.5(-7) cm, 1.1-2.4 times as long as wide; venation pinnate, the subcentric or moderately displaced, either straight, gently incurved, or randomly flexuous midrib giving rise to 5-8 major (with few intercalary), ascending secondary nerves, brochidodrome well within the slenderly corneous, often loosely revolute margin, and these to many sinuous connecting and reticular venules, the whole venation bluntly prominulous on both faces of blade. Peduncles 1.4-7 cm; capitula 14—27-fld, the globose, clavate or linear- clavate receptacle 1.5-7 mm; bracts ovate or subulate 0.3-0.8 mm, either deciduous or subpersistent; fls sessile, homomorphic, the 5-merous perianth either glabrous or puberulent externally; calyx campanulate 1.6-2.6(-2.8) x 1.1—1.7(—2) mm, the triangular-subulate or depressed-deltate teeth 0.1-0.5 mm; corolla (4—)4.2-5.8(—6) mm, the erect or ascending, ovate lobes 1-2.2 x 1-1.3 mm; androecium 18-28-merous, mostly 10.5-15.5, rarely 17-20 mm, the stemonozone <1 mm, the tube (1.2-) 1.8-3.3(-3.5) mm,  shorter than corolla; ovary glabrous, the stipe 1.1-2 mm, the oblong body 1.3—1.9(—2.2) mm, either a trifle longer or shorter than stipe. Pods l(-3) per capitulum, in profile undulately linear, when well fertilized 9-21 x 0.8-1.4 cm, 8-13-seeded, compressed but turgid, either falcately recurved through more or less half a circle, or coiled backward through 1-2 circles into a flat spiral, or equivalently randomly recurved and twisted, attenuate at base into a stipe, more abruptly cuspidate at apex, the coriaceous glabrous valves fuscous-red or nigrescent externally, dull, smooth or bluntly venulose, after dehiscence stiffly pliant under pressure, reddish tan within; funicular aril usually red or pink, sometimes whitish pink-tinged, cupping the lower 1/3-1/2 of seed; seeds in broad profile either round or pyriform 6.5-9 x 5-7.3 mm, the hard black testa lustrous, the closed or narrowly interrupted pleurogram ±3-5.5 x 2.5-4.5 mm.

At edge of hammocks, in coppice, in drought-deciduous scrub-woodland, and on dunes and coral reefs or dog’s-tooth limestones along the shore, locally plentiful throughout the Bahama Is. from Bimini and Great Abaco SE to Inagua, Caicos and Turks Is., SW to the cays off the coast of Belize. — Map 5.

-Fl. randomly throughout the year but most profusely IX—III. — Black-bead; ram’s horn.

Pithecellobium keyense may be distinguished in the field from sympatric forms of closely related P. unguis-cati by complete lack of stipular spines, but it is not so easily differentiated in the herbarium, as some flowering branches of P. unguis-cati, such as are taken for specimens, are also unarmed. When some or all leaves of P. keyense have more than four leaflets, it is distinguished by this character, but quadrifoliolate leaves are not rare in the species. In such cases, the relative lengths of petiole and pinna-rachis, the former longer in P. unguis-cati and shorter (or at least no longer) in P. keyense, a feature first stressed by Isely (1973: 113), are usually decisive.

Where the range of P. keyense overlaps that of microphyllous P. histrix there occur polymorphic populations that have been described as a distinct species, herein interpreted collectively as the hybrid P. x bahamense.