Monographs Details: Mimosa custodis 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.
Family:Mimosaceae
Scientific Name:Mimosa custodis Barneby
Synonyms:Mimosa brevipes Benth., Mimosa conferta var. guaranitica f. parvifolia
Description:Species Description - Virgate subshrubs attaining 1 m and more, closely akin to and habitally resembling M. brevipes, with eventually defoliate slender trunk and densely multifoliate homotinous stems passing upward into a simple virgate pseudoraceme 1-4 dm of small solitary globose capitula, the stems and all lf- and inflorescence-axes densely hispid with smooth yellowish setae to ±1.5-2.5 mm, the subconcolorous lfts loosely strigose-hispidulous on both faces, slenderly but continuously pallid-marginate. Stipules erect linear-lanceolate 3-8 x 0.4-0.7 mm, hispid dorsally, glabrous within, long persistent. Leaf-stalks 1.5-3.5 mm, reduced or almost so to hard livid, densely setose pulvinus, the lvs appearing almost sessile against stem; pinnae 1-jug., the recurved or deflexed rachises 2-6 cm, progressively shorter upward along stem, the interfoliolar segments ± 1.4-4 mm; lfts 11-17-jug., a little decrescent at each end of rachis, the first pair less than 1 mm distant from small subulate paraphyllidia concealed in setae, the blades oblong-elliptic from broadly semicordate base, abruptly acuminulate or mucronate, those near mid-rachis 7-11 x 3-4.5 mm, 1.9-3.1 times as long as wide, all veinless above, beneath 2-nerved from pulvinule, the slender simple, moderately displaced midrib attenuate or immersed distally, the posterior nerve expiring near or below mid-blade, the marginal nerve 0.1-0.2 mm wide, the pluriseriate cilia ascending. Peduncles 1-3 cm; capitula without filaments 7-9 mm diam., the minutely puberulent fl-buds concealed prior to anthesis by bracteal setae; receptacle setose; bracts oblance-acuminate 2.4-3.6 x 0.5-0.7 mm, in lower half embracing the fl, the tip either glabrous or setose dorsally, 1 -nerved, hispid-ciliate; flowers 4-merous 4-androus, all or most bisexual; calyx obsolete; corolla narrowly vase-shaped 2.9-3.6 mm, the ovate, shallowly concave lobes 0.7-1 x 0.6-0.8 mm, a little thickened and weakly 1-nerved distally; filaments pink, free to base, exserted 5.5-7 mm; ovary at anthesis glabrous, subsessile; ovules (? always) 2; pod unknown.

Distribution and Ecology - In dry campo, elevation not recorded, but to be expected at ±400-600 m; known only from the w. slope of Sa. de Amambay near 22-23°S in depto. Amambay, Paraguay.—Fl. XII-II.

Discussion:

Mimosa custodis is manifestly akin to M. brevipes, but differs in weakly 2-nerved, not prominently 4-5-nerved leaflets, in generally longer peduncles (10-30, not 4-14 mm), in obsolete calyx, and substantially longer flowers (2.9-3.6, not 1.5-2.6 mm). It is named in honor of Teodoro Rojas (1877-1954), keeper of Emile Hassler’s herbarium in Asunción, who collected for the first time many of the remarkable endemic plants of Amambay province.

Distribution:Paraguay South America| Amambay Paraguay South America|

Narratives:Mimosa custodis