Petunia toropiensis (Solanaceae): A surprising new species endemic from Toropi river basin in southern Brazil

A new species of Petunia (Solanaceae) is described and illustrated for the Brazilian flora. Petunia toropiensis Stehmann & Larocca is known only from a few sites along the middle Toropi river basin, in the central region of the Rio Grande do Sul state. The new species is easily recognizable by its erect or ascending habit, infundibuliform corolla with yellow tube and purple limb, yellow pollen, and erect peduncle in fruiting. The species was assessed as Critically Endangered due to the narrow geographic distribution, the few populations known, and the loss of habitat quality. A key for identification of Petunia species from Rio Grande do Sul is given. We also discuss the impact of the dams on the populations of the new species and the conservation efforts needed.