SUMMARY
The genus Simira is represente in Brasilian Amazonia by eight species: S. pisoniiformis, S. macrocrater, S. corumbensis, S. tinctoria, S. hadrantha, S. rubescens, S. paraensis and a new species from Mato Grosso. Of these, S. rubescens has the widest distribution, ocurring frequently in Brazilian, Venezuelan and Peruvian Amazonia, S. pisoniiformis occurs in Brazilian and Peruvian Amazonia , buth there is also a distinct population in the south of the state of Bahia. S hidrantha, previously only known in Peruvian Amazonia, is cited for the first time in Brazil. The principal taxonomic characteristics to identify the species are the aestivation and hairiness of the corolla, the number of pairs of secundary veins in the leaves and the texture and dehiscence of the capsule.