Mimosa filipes

  • Title

    Mimosa filipes

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Mimosa filipes Mart.

  • Description

    189. Mimosa filipes Martius, Flora 21(2, Beibl. 4-5): 52 [=Herb. fl. bras. 132]. 1838. — ". . . in campis  "mimoso"dictis ad Serra Branca in Prov. Piauhiensi superiore, Majo [1819] florens."—Holotypus, M (2 sheets)! = F Neg. 6180 = IPA Neg. 1345.

    M. filipes sensu Bentham, 1841: 373, 1875: 432, 1876: 370; Lewis, 1987, fig. 9E.

    Slender, either erect few-branched or finally diffusely many-branched, remotely foliate herbs 3-10 dm, flowering the first season when appearing monocarpic but potentially suffruticulose, glabrous below the ovary and eglandular, the smooth ribbed stems either green or purplish, the olivaceous lfts thin-textured, the small globose capitula mostly scattered in axils of middle and upper lvs and surpassed by them, but some pseudoracemose and exserted. Stipules submembranous, narrowly ovate- or lance-aristate 1-1.5 mm, persistent. Leaf-stalks filiform, widely ascending (1.3-)2-4.5 cm, charged at apex with an acicular interpinnal spicule; pinnae 1-jug., their rachis 5-13 mm, the interfoliolar segments 1-2.5 mm; lfts (3-)4-7-jug., little graduated, in sleep sub vertically imbricate, the first pair (1-) 1.5-3 mm from pinna-pulvinus, all oblong-elliptic or narrowly obovate obtuse 2-9 x 0.7-3 mm, the margin plane, the blade faintly 2-nerved from pulvinule, the costa subcentric. Peduncles solitary or geminate, filiform 9-40 mm; capitula without filaments 3-4 mm diam., prior to anthesis moriform, the bracts vestigial, less than 0.5 mm; flowers 3-merous 6-androus glabrous, some proximal ones staminate, the rest bisexual; calyx membranous ±2 mm; corolla turbinate-campanulate 1.5-1.8 mm, the obovate obtuse, shallowly concave, faintly 1 -nerved, greenish or purplish lobes ± 1 mm; filaments pink, monadelphous through ±0.2-0.3 mm, exserted 3.5—4 mm. Pods solitary or geminate, randomly spreading- ascending, the broad-linear, nearly straight planocompressed body 25-38 x 3.5-5 mm, contracted at base into a stipe 2-4.5 mm, the shallowly undulate replum 0.25-0.3 mm diam., either smooth or armed with divaricate tapering setaculei to 0.5-2 mm, the thin, green or purplish, densely minutely villosulous or glabrous atomiferous valves becoming brownish papery, breaking when ripe into (5-)6-9 almost square, individually indehiscent, free-falling articles; seeds compressed-rhomboid ±3-4 x 3 x 0.6 mm, the testa pale fawn or light brown, minutely granular, the areole ±1.5 x 1 mm.

    In open sandy or stony places in campo rupestre, campo sujo, cerrado and caatinga, 300-1000 m, apparently not common but inconspicuous and easily overlooked, scattered over eastern Brazil from s. Maranhão to far w. Pernambuco, s. through lower S. Francisco valley and Chapada Diamantina in Bahia to Sa. do Espinhaço in centr. Minas Gerais.—Fl. I-IV. Map 25.

    Glabrous unarmed, remotely leafy stems, tiny stipules, a single pair of pinnae with a spicule between them, 3-7 pairs of glabrous leaflets and tiny capitula contribute to the unique facies of M. filifolia. Young plants, like those collected by Martius, appear monocarpic, but older ones develop a distinctly suffruticose base; probably none are obligately annual. So far as present evidence goes, the pod in populations of M. filipes from Bahia northward has a perfectly smooth replum but the valves may be either simply puberulent, both puberulent and granular, or simply granular. In Minas Gerais, from Grão Mogol south to Diamantina, the replum is consistently fimbriate along its dorsal and lateral ribs with weak setiform aculei, and the valves are consistently puberulent. Perhaps two weakly differentiated varieties may eventually be recognized.