OOOH LAAH! A Heartthrob Eastern Time! I have been dreaming wistfully of this species for years. I was sure it was extinct. I was sure nobody in the world would ever see it again in the cellulose, including me. I was wrong. Known from < 5 total collections throughout history, it is with great happiness and relief to report that Ruellia longifilamentosa is in fact extant in the wild as of January 2015. Its rarity is presumably in part related to its habitat requirements: high quality, intact, wet, native forest at mid elevations, which are increasingly threatened (or already demolished) throughout the Neotropics. This habitat need applies to most other bat-pollinated (or please at least allow me to say: bat-adapted) Ruellia. As such, protecting these mid-montane mesic ecosystems will be vital to long-term preservation of an entire pollination syndrome of plants in this lineage. This population was collected in Cundinamarca, near Finca La Concepcíon along the banks of the Río Guane. The length of the exserted stamens (that surpasses the total length of the corolla) is enough to make you, too, dream wistfully.
Ruellia longifilamentosa is a small tree to 3m. Bat pollination in Ruellia seems to be correlated with this treelet growth form (as well as production of flowers in long, terminal panicles). It is in fact the case based on a formal analysis that I conducted waaaaaaay back in graduate school, but never published. Oh well – so much to do, so little time. In any event, this correlate must have something to do with getting ones flowers up off the ground and in a more aerial position for bat visitation. Says me. Ruellia longifilamentosa is sister to R. humboldtiana (red, bird), both of which are part of the Ruellia tubiflora (white, big bee) clade. That’s a lot of floral diversity over a small phylogenetic distance, if that’s the sort of thing that turns you on….
Wild collected, Colombia, Godden et al. #268 (COLO) and Tripp et al. #5262 (COLO); Photo by Grant Godden
What happens when we let special places remain special places, without intervening, disrupting, leveling, developing, or otherwise disturbing such special habitats? Here is what I know about Ruellia macarenensis. Prior to our visit to Colombia in January 2015, this enigmatic, highly restricted-endemic species was known only from its type collection, which was made in dense forests along the banks of the Río Güejar near the confluence with Río Zanza at the northern edge of the Cordillera Macarena. It was flowering in August of 1950. The Serranía de la Macarena is a biodiversity-rich isolated massif that lies due east of the Cordillera Oriental of Colombia. It represents a unique ecological transition zone between Amazonian, Orinoco, and Andean biotas.
Fast forward 65 years and our field team revisited the type locality to find, all these years later, the population to still be extant, albeit in fruit only in January. If it weren’t for the flowering material available on the holotype and its duplicates, I would swear that Ruellia macarenensis was conspecific with Ruellia jussieuoides. But the type (and protologue) clearly indicate a very different floral morphology of R. macarenensis compared to R. jussieuoides, thus readily distinguishing the two morphologically as different species. I do however predict close relationship between them – both share a conspicuous presentation of primary and secondary veins raised far about the leaf blade surface. Whereas Ruellia macarenensis is highly restricted and endemic to this one small corner of Earth, Ruellia jussieuoides occupies a much broader range that includes large portions of the Amazon north to mesic southern Mexico. Sounds like a classic case of peripatric speciation to me.
Wild collected, Colombia, Godden et al. #254 (COLO) and Tripp et al. #5248 (COLO); Photo by Grant Godden
Yongbin is a postdoc and started working with Erin in the fall of 2015. He is from Shan Dong, China and got his PhD in Molecular Biology from the South Dakota State University in 2014. His graduate study focused mainly on the utilization of Next Generation Sequencing to uncover genes involved in plant-microbe interactions. He moved to Denver, Colorado in 2015 to escape the harsh weather in South Dakota. Over the years he has further developed his interests in bioinformatics, data mining, and programming. As a postdoc, he is working on evolution of the anthocyanin pathway in Ruellia, in attempt to unveil constraints on floral color evolution. In his free time, he enjoys traveling and cooking.
His CV is available here.