A new species of Mimosaceae from Brazilian Amazon, called Mimosa dasilvae A. S. Silva & R. Secco is described and illustrated. The new taxon belongs to sect. Habbasia ser. Piresianae and shows affinities with M. piresii Barneby, from which differs specially in long, liana-like habit, smaller, ventrally glabrous and lustrous leaflets, and very small floral bracts.
Mimosaceae; Mimosa; Taxonomy