Very cool plant in a very cool clade that has some evolutionary secrets to unlock… This species is so very clearly related to R. paniculata and R. galeottii, among others in the clade (see Tripp 2007 and Tripp & Manos 2008). Like R. paniculata, it is extremely widespread, occurring from Mexico through Central American and continuing south. Ruellia galeottii, on the other hand, is a restricted endemic to hot, semi-deciduous forests of southern Mexico.
The floral colors (plus their shapes) are what intrigue me. Ruellia inundata is a dark pink – mauve of sorts whereas R. paniculata and R. galeottii are purple. There is a long story to discover here….
Best population ever seen of this species: atop some little known, little visited, little appreciated, but most remarkable EVER Mayan ruins in Campeche: Calakmul Biosphere Reserve. Check it out… you and the toucans.
Wild collected, Costa Rica, Tripp & Deinert #121 (DUKE); Photo by Erin Tripp