I just love this species SO much. (I also love those tiny portable rulers that Carrie takes with her everywhere). Ruellia bourgaei is most certainly is among my top 5 favorites in the genus. WHOMPING bat-pollinated flowers…. probably the biggest in the genus. This species also produces the biggest fruits yet known in Ruellia. They are humongous – over 5 cm in length.
In the photo to the right, check out the filament curtain. This structure, which is unique to Ruellieae (see Tripp et al. 2013, International Journal of Plant Sciences), is a partition formed by the fusion of filament pairs and their adnation to the corolla wall. Who knows its function (but see Manktelow 2000 for some excellent hypotheses)… maybe in preventing nectar evaporation, maybe for overall floral stabilization, maybe in some other pollination-related function, or maybe nothing at all.
Ruellia bourgaei is endemic to Mexico, with most extant populations occupying the Sierra Madre del Sur. Part of the “Chiropterophila” or “bat loving” clade. Flowers at night, naturally. And, naturally, another plant named after a dead white guy – sigh.
Wild collected, Mexico, Tripp & Kiel #428 (RSA-POM); Photo by Erin Tripp