Monographs Details: Mimosa setosa subsp. granitica 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
Description:Subspecies Description - Stems and lf-stks variably hispid with plain setae, villosulous with minute plain hairs, glandular-setulose, or setaculeate with forwardly curved, weakly vulnerant prickles to 2—4 mm, in indumentum ambiguous between subsp. setosa and subsp. paludosa, different from both in venation of relatively broad lfts, as described in key to divisions of M. setosa; pinnae 5-12-jug.; lfts of longer distal pinnae (16-)22-38-jug., the longer ones 5-8 x (1.8-)2-2.6 mm.

Distribution and Ecology - Moist rocky places in campo rupestre, 10001250 m, locally common on Chapada dos Veadeiros at points ± 10-20 km n. and n.-w. of Veadeiros, e.-centr. Goiás, Brazil.—Fl. II-V, fr. remnants long persistent. Map 28.

Discussion:

M. granitica Barneby in sched., nom. nud. = the vulnerantly setaculeate state of the subsp.

M. dawsonii Barneby in sched., nom. nud. = the simply setose and glandular-villosulous state of the subsp.

The six known collections of subsp. granitica, while alike in venation of leaflets, are extraordinarily diverse in indumentum. Stems of the type are sharply setaculeate but glandular; those of Dawson 14780 (NY) are thinly stiffly setose and sparsely glandular-setulose; those of Irwin 33045 (NY) are densely softly villosulous and glandular-setulose but unarmed and almost without plain setae. In preliminary studies I referred the material to two species, for I had not yet accepted, in defiance of long tradition, the assimilation into one species of armed M. paludosa and unarmed M. setosa. I now interpret these superficially different forms found concentrated on the heights of Chapada dos Veadeiros as constituting trivial variants of one taxon best subordinated to M. setosa sensu lato.

Distribution:Brazil South America| Goiás Brazil South America|