ABSTRACT
The taxonomic study of Mimosa L. in the Ipanema Valley was based on morphologic analysis of fresh material or herbarium specimens, as well as field observations. Eleven taxa, distributed in three sections, were found: 1) Mimosa sect. Batocaulon (M. adenocarpa, M. arenosa, M. gemmulata var. adamantina, M. lewisii, M. misera, M. ophthalmocentra and M. tenuiflora); 2) Mimosa sect. Habbasia (M. somnians); and 3) Mimosa sect. Mimosa (M. hirsutissima var. hirsutissima, M. modesta var. ursinoides and M. sensitiva var. sensitiva). The main characters used for delimitation of the species were type of indumentum, inflorescence morphology, number of pinnae, leaflets, perianth elements and stamens, as well as aspects from the fruit. Most species occur in caatinga vegetation, only M. hirsutissima var. hirsutissima, M. gemmulata var. adamantina, M. misera and M. sensitiva var. sensitiva occur in evergreen shrubby vegetation.
Key words:
Mimosa; Mimosoideae; taxonomy; survey; floristics; Brazil