Here’s an opportunity. Ruellia amoena sure looks a lot like Ruellia foetida, but has pigmented instead of white flowers. One often finds these two species sympatrically, or nearly so. A “must study” taxon pair evolutionarily.

Wild collected, Mexico, Tripp w/ Kiel, & Hasenstab-Lehman #1225 (RSA-POM); Photo by Erin Tripp

Gaudy Gaudy Gaudy! Carrie Kiel would love the flowers of this species, which sit atop vegetative portions of a rare growth form (vining) in the genus. One must really and truly appreciate the epithet. ‘affinis’. Hey – it’s got affinity to something, after all…!

Update (Aug 2016): As it turns out, Ruellia affinis is rather common in mesic forests of eastern Brazil. It really is a vine, and it really does looks strange in the field, but I will happily accept this species as a Ruellia. Hey – the genus does more interesting things morphologically than does my own…

I still do not know what lineage this plant belongs to – a classic rogue taxon in phylogenetic speak – perhaps RADseq data will soon resolve…

Wild collected, Brazil, Erin Tripp #5887 & #5889 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Cíntia Kameyama, Erin Tripp

Just LOOK at that lower corolla lobe – absolutely amazing, and one of a kind. Kyle and I discovered and named this species after the acetabulum…a fine wine drinking vessel from ancient Rome. Nothing else in Ruellia comes close to this sort of odd morphology.

Ruellia acetabula is at present known only from Namibia, where it loves the very dry rocky hillsides of the northwestern province Kunene. This species is clearly related to a group of SW African taxa that have a unique “2+2+1” calyx morphology, and smell of citronella. This group includes Ruellia marlothii, R. kaokoana, R. aspera, and R. diversifolia. See Tripp & Dexter 2012, Systematic Botany.

Wild collected, Namibia, Tripp & Dexter #871 & #1991 (RSA-POM); Photo by Erin Tripp

On the petite side of species in the genus…yep – that’s the entire plant. Welcome to Ruellia. Runs the gamut.

Wild collected, Mexico, Tripp & Acosta #168 (DUKE); Photo by Erin Tripp

Ruellia abbreviata Gibson. Protologue: (Fieldiana, Bot. 34: 78-79. 1972.)