Monographs Details: Mimosa multiceps Barneby
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1991. Sensitivae Censitae. A description of the genus Mimosa Linnaeus (Mimosaceae) in the New World. Mem. New York Bot. Gard. 65: 1-835.
Description:Species Description - Glabrous herbs, the stout, almost simple castaneous stems apparently erect from woody root, near middle ± 3 mm diam., the few paucipinnate and paucifoliolate lvs much surpassing the paired and fasciculate axillary peduncles. Stipules narrowly lanceolate 1.5-3 mm, 1-nerved. Leaf-stalks 5-9.5 cm, subterete, the petiole proper 3.5-5.5 cm, the longer or single interpinnal segment 1.5-2 cm; interpinnal spicules 0; pinnae 2-3(-4)-jug., the rachis 1-2.4 cm, the longer interfoliolar segments 3.5-8 mm; lfts 2-3-jug., the first pair 4-8 mm distant from subulate paraphyllidia, in sleep folded subvertically over rachis but not or scarcely imbricated, the dark-olivaceous blades a little accrescent distally, in outline obliquely obovate-elliptic from semicordate base, the larger ones 8-11 x 4-6.5 mm, all veinless above, weakly 3-4-nerved dorsally, the midrib only slightly displaced, secondary venules few and faint. Peduncles (l-)2-7 per lf-axil, 2-5.5 cm; capitula subglobose, without filaments ± 6-7 mm diam., the claviform receptacle ± 1 mm; bracts linear-oblanceolate 0.8-1.2 mm; flowers 4-5(-6)-merous diplostemonous, glabrous; calyx campanulate 0.3-0.6 mm, the orifice truncate or shallowtoothed; corollas mostly bisexual, turbinate-campanulate 2.8-3.2 mm, the ovate 1-nerved lobes ± 1 mm; filaments pink (drying yellowish), fused at base into a necklike stemonozone 0.3-0.7 mm, exserted 5.5-7.5 mm; ovary glabrous, at early stage of maturation sometimes minutely granular laterally. Pods to five per capitulum, subsessile, in profile linear, erratically decurved, when fully fertile attaining 70 x 7 mm, 10-13- seeded, the smooth replum 0.5-0.7 mm wide, shallowly constricted between seeds, the brown, finely reticulate glabrous valves low-colliculate over each seed, when ripe breaking up into free- falling articles ± 5 mm long; seeds not seen.
Distribution and Ecology - In cerrado, on sandy substrates, ±250-600 m, apparently local at lat. 17°-18°30'S in s.-e. Mato Grosso (n.-w. of Alto Araguaia) and adj. Mato Grosso do Sul (mun. Coxim), Brazil.—Fl. VI- VIII. Map 22.
In habit M. multiceps stands between the erect, ephemerally leafy M. piptoptera and the more conventional, diffuse and permanently foliate species such as M. gracilis sens. lat., or M. burchellii. In this context it is readily distinguished by leaf-formula, subterete leaf-stalks, relatively ample leaflets, and plump capitula. The flowering season, June to August, is further remarkable. The tender texture of the leaves that accompany flowers suggests rapid growth from a xylopodium such as occurs in Chamaecrista claussenii (Benth.) I. & B., also a cerrado subshrub flowering in the dry season. In the available sample the flowers appear to be normally tetramerous, a few pentamerous; and I found in Hatschbach 33176 (NY) one hexamerous flower with 12 stamens and two gynoecia.
Distribution:Brazil South America
| Mato Grosso Brazil South America
| Mato Grosso do Sul Brazil South America