Monographs Details: Mimosa aurivillus var. calothamnoides 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:Variety Description - Shrubs 1.5-2 m, the stems and lf-stks tomentose with setae to 0.3-1.3 mm plumose from base to tip, the lfts stellate on both faces but thinly so and dark brown (when dry) above, beneath densely tomentulose with interlocking stellae; stipules 2-3.5 mm; leafstalks 1—3(—4) cm, the petiole proper 5-9(-14) mm; leaf-formula ii-iii/7-10(-13), the larger lfts 5-10 x 3.5-5 mm; capitula without filaments 6-9 x 5-6 mm; calyx 0.1-0.2 mm; corolla 2-2.4 mm; pods 10-26 x 4-5 mm.

Distribution and Ecology - In thickets on steep rocky hillsides, on stream-banks and at edge of gallery woodland, 1000-1250 m, locally plentiful high on the w. slope of Sa. do Espinhaço in mun. Datas and Gouveia, near 18°30'S in centr. Minas Gerais.—Fl. XI-III.

Discussion:

The var. calothamnoides is crucial to the classification of M. aurivillus sensu lato because in it are combined characters previously thought to distinguish the closely related M. aurivillus sens. str., M. calothamnos, and M. sordida: the short leaf-stalks and relatively few leaflets of aurivillus; the dorsally tomentose leaflets of calothamnos, thinly stellate above and of the same number as in sordida (=var. sordescens of this account). The vars. aurivillus and calothamnos are sympatric in the range of var. calothamnoides, which may perhaps represent a set of localized, self-perpetuating hybrids. However, where var. calothamnos and var. aurivillus coincide further south, as on Sa. da CaraƧa, no intermediates have been detected. A specimen from Sa. CaparaĆ³ in southeastern Minas (H. C de Lima 2575, RB), superficially similar, requires critical revision.

Distribution:Brazil South America| Minas Gerais Brazil South America|