Monographs Details: Mimosa radula var. imbricata (Benth.) 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
Synonyms:Mimosa imbricata Benth., Mimosa imbricata var. multijuga Benth., Mimosa paraizensis Taub.
Description:Variety Description - Stems commonly 2—3 erect or stiffly assurgent, simply virgate or paniculate distally, (7—) 10—15 dm, densely clothed from near base, where 3—6 mm diam., to efoliate or proximally leafy-bracteate pseudoraceme with sessile, usually crowded and recurved, sometimes more distant, ascending and outwardly arcuate lvs spaced 1-3 cm apart, like leaf- and inflorescence-axes at once densely puberulent and either densely hispid- or silky-pilose with spreading-incurved, subretrorse, or rarely ascending, smooth or at base microscopically scaberulous setae to (1-) 1.5-3.5 (-4) mm, the lfts pilosulous on both faces, palmately 3-5-nerved beneath; rachis of commonly retroarcuate and obliquely geotropic pinnae 2- 5.5(-8) cm, the longer interfoliolar segments 2- 5(-6) mm, often shorter in distal than in proximal lvs but sometimes subuniform the length of stem; lfts (7-)8-18(-22)-jug., all obliquely lanceolate or semi-ovate 9-18 x 3-5.5 mm, deltately acute, the midrib dividing blade 1:2.5-4.5; peduncles (1.5-)2-4 cm; capitula without filaments (7-)8-12 mm diam., prior to anthesis conelike and pallid-setose or rarely submoriform; bracts (2.5-)3-5 x 0.3-0.5 mm; calyx 2.7- 4.2(-4.8) mm; corolla (3.5-)3.7-5.2(-6) mm.

Distribution and Ecology - In campo and open cerrado, often on red sandy soils, 900-1200 m, locally plentiful in s.-e. Goiás, Brazil and Distrito Federal, s.-ward from sources of rio Paranã (S. João da Aliança; S. Gabriel de Goiás) to Sa. de Facão (n.-e. of Catalão), within lat. 14°50'-l 8°S, thence extending feebly e. across Sa. da Tiririca into far w. Minas Gerais (Paracatú).—Fl. XII-III(-IV).

Discussion:

Being locally common in the cerrado of the Federal District and a tall, conspicuous wandlike plant impossible to overlook, var. imbricata is the most frequently collected and consequently the best known variety of M. radula. Leaves all sessile against the stem and leaflets at once relatively small (none over 2 cm long) and pubescent on upper face are the only discriminatory features that now seem to detach it from the rest of M. radula. The var. semitonsa, with almost the same number and size of leaflets, has lower leaves petiolate and the leaflets themselves are glabrous above, while the other varieties have either fewer leaflets, or much larger leaflets, and when their leaf-formula is similar have obviously stalked lower leaves.

Distribution:Brazil South America| Distrito Federal Brazil South America| Goiás Brazil South America| Paraná Brazil South America| Minas Gerais Brazil South America|