Here is a special species from the Cabinets of Curiosities of Socotra… home to so many peculiar plants, many of them endemic, many of them Acanths. I have no idea how this plant made it into cultivation, but one sees it flitting about various living collections across the world (especially those of the cool kids). It flitted its way into…. then out of… mine. If you are growing it, please get in touch – I’d love to be re-acquainted.
In addition to all of the other reasons you might just come to LOVE this species (e.g., those enchanting flowers, succulent leaves, or its furtive distribution), this plant has THE COOLEST CYSTOLITHS (check it – ‘rock sacs’) of ANY ACANTHACEAE. It’s true. They are dimorphic! Ruellia insignis produces the cigar shaped cystoliths typical of most other Acanths but in addition, it produces others shaped like a medieval mace! Notice how you can see them just under the upper leaf epidermis. This is heavy stuff…
This belongs to an early diverging grade that is paraphyletic with respect to Neotropical Ruellia. We have a lot of work to do in reconstructing this region of the phylogenetic ‘hood. Most immediately: we’d like to know how closely related this species is to other Ruellia endemic to Socotra, such as Ruellia carnea (which, consider yourself among the chosen few if you have ever seen this plant in the wild… I haven’t, and may never….).
(Formerly) cultivated, RSABG Greenhouses, originally from Socotra (Yemen), Not Vouchered; Photos by Erin Tripp