Mimosa turneri

  • Title

    Mimosa turneri

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Mimosa turneri Barneby

  • Description

    58. Mimosa turneri Barneby, Brittonia 38:4, fig. 2. 1986.—"United States. Texas. Presidio Co.: . . . along Rio Grande 21 road miles (34 km) upstream from Lajitas, 30 May 1985 (ripe pods, few flowers), R. Barneby 17970"—Holotypus, NY!; isotypi, TEX! US!

    Stiffly branched microphyllous shrubs attaining 2 m, with divaricate long-shoots clad in pallid shreddy epidermis and armed at or below most nodes with straight or recurved, early blanched aculei 1.5-5 mm, glabrous except for minutely filamentous-tomentellous stipules and randomly puberulent lf-stks, the subglobose capitula on brachyblasts along annotinous branches, the lvs dimorphic, those of long-shoots solitary, early deciduous, most fasciculate on hemispherical brachyblasts, the lfts firm, pale green or glaucescent concolorous. Stipules 0.5-2 mm. Leaf-formula of primary lvs i-ii(-iii)/2-3, of fasciculate lvs i/2, the petiole (1.5—)2—11(—14) mm, dorsiventrally compressed and 2-sulcate, a little dilated distally; lfts of distal pair 1.5-4 x 0.6-2 mm. Peduncles 4-16(-20) mm; capitula without filaments (5-)6-8 mm diam.; pedicels 0.4-1.5 mm\ flowers 5-merous 10-androus; calyx turbinate-campanulate 0.45-0.9 mm, the subtruncate rim glabrous or minutely ciliolate; corolla 2-2.8 mm, the ovate lobes 0.5-1.1 mm; filaments pink, shortly monadelphous around stipe of ovary, exserted 3-4.3 mm. Pods subsessile or shortly stipitate, the body in profile undulately linear, arched downward or twisted, (15-)25-60 x 5-8 mm, (2-)3-8(-9)-seeded, the replum either unarmed or the ventral suture with random erect aculei, the glabrous, when ripe brownish-stramineous valves bullately elevated over each seed, breaking up into individually dehiscent, free-falling articles 6-9 mm long.

    In desert matorral on limestone and volcanic substrates, 650-1500 m, apparently of bicentric range: along Rio Grande in trans-Pecos Texas (Hudspeth, Presidio and Brewster cos.) and presumably across river in Chihuahua, Mexico; in centr. Coahuila and adj. Nuevo León, Mexico (Barneby, 1986, fig. 1, map).—Fl. IV-V.

    Closely akin to M. borealis, but different in the conventionally sympetalous corolla and simplified foliage, in this respect approaching the further specialized M. unipinnata.