Mimosa cordistipula

  • Title

    Mimosa cordistipula

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Mimosa cordistipula Benth.

  • Description

    180. Mimosa cordistipula Bentham, J. Bot. (Hooker) 4: 411. 1842.—"Serra Jacobina [Bahia, Brazil], Blanchet, n. 2597."—Holotypus, K! = NY Negs. 1872, 11665; isotypi, BM! F! = F Neg. 54823, G! = F Neg. 28204, NY! P! W!

    M. cordistipula sensu Bentham, 1875: 431, 1876: 368; Lewis, 1987, fig. 7H, J.

    Awkwardly branched depressed or ascending shrublets 1.5-7(-10) dm, the old stems scaly with marcescent stipules or lf-stks, the homotinous ones densely leafy and villous with fine white spreading hairs to 0.8-1.3 mm often but not always mixed with shorter fine gland-tipped setulae, the foliage similarly but more thinly pubescent and the lf-stks sometimes remotely aculeolate, the small glossy thick-textured lfts glabrous or almost so facially, ciliolate or glandular-ciliolate, the globose capitula from a few distal lf-axils, well exserted from foliage. Stipules ovate- or lance-acuminate from subcordate base, 2.5-5.5 x 1-2 mm, the stout, dorsally prominulous midrib excurrent as a yellowish spinule, the 2-3 lateral nerves much weaker. Leaf-stalks stiff 6-23 mm, attenuate beyond last pair of pinnae into a yellowish spinule, the petiole 1-4 mm, the longer interpinnal segments l-3(-4.5) mm; spicules 0, but minute livid granules subtending the pulvini of pinnae; pinnae 3-, 3-4-, 4-7-jug., the rachis (5-)7-14 mm, at apex spinulose like lf- stk, the longer interfoliolar segments 0.5-1 mm; paraphyllidia 0; lfts 7-9-, 10-12-jug., subdecrescent at each end of rachis, in sleep imbricate obliquely upward, the longer ones narrowly oblong or oblong-elliptic obtuse 2-3 x 0.6-1.1 mm, all centrically 1-nerved dorsally. Peduncles ascending 2-5.5 cm, sometimes divaricate after anthesis; capitula without filaments 5.5-7.5 mm diam., prior to anthesis either moriform or incipiently conelike, the bracts sometimes projecting from between fl-buds; bracts linear-oblanceolate 1-3.5 mm, usually membranous flaccid, but the midrib sometimes indurated; flowers 3-merous 6-androus, the lower ones staminate, the rest bisexual; calyx 0.5-0.7 mm, the short teeth sometimes thinly ciliolate; corolla membranous, narrowly turbinate or vase-shaped 2.8-3.2 mm, the ovate lobes 0.9-1.5 mm, at cucullate apex callous-thickened and externally villosulous; filaments pink, monadelphous at base through less than 0.5 mm, exserted 5-6 mm. Pods mostly 1-2 per capitulum, subsessile, in profile linear straight 25-30 x 3.5-4 mm, the shallowly undulate replum 0.4-0.6 mm wide, the firmly papery, densely puberulent valves low-colliculate over each seed, when ripe breaking up into 5-7(-8) free-falling articles ±4.5 mm long; ripe seeds not seen.

    In campo rupestre or occurring as an element of depauperate caatinga scrub in shallow soils on sandstone outcrops, 1000-1150 m, local on the heights of Chapada Diamantina between lat. ± 11°-13°30'S in interior Bahia, from Sa. da Jacobina s. through Sa. do Tombador to Sa. do Sincorá.-F. I-VI.

    A species of marked character, notable for xeromorphic shrubby habit, broad stipules, small crowded leaves, and especially for the spinulose tip of stipules, leaf-stalks and pinnae. Even in its restricted range M. cordistipula exhibits a diversity of indumentum characteristic of many much more widely dispersed members of the genus. While the stems and foliage are constantly villous in varying density, on Sa. da Jacobina they are also glandular-setulose and the leaf-stalks are dorsally aculeolate. On Sa. do Sincorá pin-glands and prickles are entirely wanting. On intervening Sa. do Tombador, within a radius of 20 km of Morro do Chapeu, the several known populations vary from both glandular and prickly (Irwin 32348, NY) or glandular but not prickly (Mori & Boom 14522, NY) to neither glandular nor prickly (Irwin 32650, NY).

    In Flora brasiliensis Bentham described the flower of M. cordistipula as tetramerous, but voiced the suspicion that they should be trimerous as in related species. I have found none but trimerous flowers in the isotype at NY or in any of seven modem collections studied.