Another difficult purple Ruellia from Brazil. This species was described (under a different genus) by Nees in Flora Brasiliensis, in 1847. I’d probably have nothing further to say about this plant if it weren’t for insight shared by Cecilia Ezcurra back in 1993 (I’ve said it before and I’ll say it again: my PhD dissertation would have been impossible without her as well as Tom Daniel’s foundational work in Ruellia taxonomy). In her 1993 pub, Cecilia notes that R. dissitfolia is endemic to central Brazil–Goiás, Minas Gerais, and São Paulo specifically–and is characterized by having basal, obovate leaves, dense white pubescence, and relatively large flowers.
This species is most likely to be confused with Ruellia brevicaulis. See Ezcurra (1993) for further distinguishing features.
The collection cited below is actually from Bahía (not far from Goiás)…. could it be?
Wild collected, Brazil, E. Tripp #5918 w/ Nico Medina & Cintia Kameyama (COLO); Photos by Erin Tripp
Wild collected, Brazil, Tripp #5918 w/ Nico Medina (COLO); Photos by Erin Tripp