Ruellia helianthemum

We found Ruellia helianthemum on one of the most memorable days of my life. Cíntia’s student Rodolfo tipped us off to a remarkable landscape full of sympatric Ruellia species not far from Cavalcante, north of Parque Nacional Chapada dos Veadeiros. We pointed the car in that direction and with only a half glow of remaining sunlight, punched it 130 km as fast as possible. We landed in the most spectacular landscape of mixed campos rupestre and cerrado and found nothing short of 5 sympatric Ruellias.

Ruellia helianthemum is a most distinctive species and one that I suspect was named as such because of the dense, golden trichomes that characterize leaf surfaces (this population densely pubescent but not so golden). We found this species in abundance on flat, sandy soils, about 60 km W of Cavalcante, en route to Serra do Tombador. The plants were extremely sticky-glandular and fruits were severely predated.

What a GREAT day.

Wild collected, Brazil, Erin Tripp #5932, w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp, Cíntia Kameyama

Ruellia eurycodon

Score BIG TIME. Sort of like shooting the moon if you are playing Hearts, but way bigger. Ruellia eurycodon is one of two bat-adapted species of Ruellia that we encountered on our August 2016 fieldtrip (check out the other before you close your web browser: Ruellia verbasciformis). Ruellia eurycodon will be remembered affectionately for many reasons, only one of which was the extremely sweet floral fragrances that flowers produce. Floral fragrance is essentially unknown among all Neotropical Acanthaceae (some OW members of the family are fragrant). Why the exception in this case? How are Acanths as a whole so “successful” without fragrance? Better to back up and ask, what is the relationship between fragrance and fitness, summed across all angiosperms? Is the production of fragrance, widely regarded as a crucial component of a suite of reproductive characters, driven by ecology or limited by historical constraints and an inept underlying genomic architecture? Are Acanths somehow fragrant in a way we have failed to detect in this 21st Century? All questions unanswered, all ready for an enterprising student. Be the one.

Alas, is it perfume from a dress, that makes me so digress?

Ruellia eurycodon is a small tree to ~3m with dull yellow flowers that open at night. We found the species abundantly flowering and fruiting in an intact semi-evergreen forest that comprises Reserva Natural Vagafogo, not far from Pirenópolis. The very kind family-owner of this reserve welcomed us into his property, assured us we would find the species (he was right!), then fed us coffee. Ruellia eurycodon is related to R. exserta and R. steyermarkii–both bat pollinated (the former from Brazil, the latter from Venezuela) as well as several red-flowered species including Ruellia inflata.

Wild collected, Brazil, Erin Tripp #5942, w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp, Cíntia Kameyama

Ruellia erythropus

For several years (5 to be precise), Manuel and I had on hand collection #514. We made this collection in the dry forests of Lara. It was the crappiest of specimens – only the tiniest quantity of material available for vouchering. We did so, but couldn’t put a name on it. It perplexed us to no end. We finally gave up. We wrote the treatment (“Venezuelan Ruellia: A Monograph) and sunk this one into the undetermined collections section. Incredibly unsatisfying. Haunts the taxonomist at the oddest hours. We submitted the treatment. It came back with favorable reviews. We began putting final touches on the work, still lacking resolution on the identity of #514….

Finally, just before resubmitting and sending the treatment to print, I came upon the answer. Woke up one snowy Saturday morning thinking about Ruellia erythropus… a species I had seen only in herbaria. I checked the type. I checked the protologue. I checked our photographs. Five years later, the mystery was solved.

Ruellia erythropus is a wonderful species for so many other reasons other than an excellent start to a snowstorm. It is one of the very few species within the entire genus with a 3-parted calyx and capsules that have fracturing placenta (yep – as cool as it sounds… sort of like plants doing gymnastics; see Tripp 2007; McDade & Tripp 2008; Tripp et al. 2009).

Wild Collected and fondly remembered, Venezuela, Tripp & Lújan #514 (RSA); Photo by Erin Tripp

Ruellia dissitifolia

Ruellia dissitifolia_ET5918 (5).jpg

Another difficult purple Ruellia from Brazil. This species was described (under a different genus) by Nees in Flora Brasiliensis, in 1847. I’d probably have nothing further to say about this plant if it weren’t for insight shared by Cecilia Ezcurra back in 1993 (I’ve said it before and I’ll say it again: my PhD dissertation would have been impossible without her as well as Tom Daniel’s foundational work in Ruellia taxonomy). In her 1993 pub, Cecilia notes that R. dissitfolia is endemic to central Brazil–Goiás, Minas Gerais, and São Paulo specifically–and is characterized by having basal, obovate leaves, dense white pubescence, and relatively large flowers.

This species is most likely to be confused with Ruellia brevicaulis. See Ezcurra (1993) for further distinguishing features.

The collection cited below is actually from Bahía (not far from Goiás)…. could it be?

Wild collected, Brazil, E. Tripp #5918 w/ Nico Medina & Cintia Kameyama (COLO); Photos by Erin Tripp

Wild collected, Brazil, Tripp #5918 w/ Nico Medina (COLO); Photos by Erin Tripp

Ruellia curviflora

Three weeks in the field in Brazil are worth some amount that is hard to quantify in any existing currency – but perhaps a decade of research in the herbarium?

Brazil is without doubt home to the most incredible diversity within the genus that I have ever encountered. Ruellia curviflora was just one of many amazing finds from coastal Bahia. This species is somewhat unique in its affinity for wetter forests, where it co-occurs with Ruellia affinis.

My favorite population was in Refugio Serra do Teimoso, near Juçari. This is a very special reserve loaded with old growth virgin tropical forest. Even though we found Ruellia curviflora in abundance near the entrance, Nico and I decided to hightail it to the summit. We found other incredible Acanths along the way. I will never forget the splendor of that entire mountainside.

Note the glabrous leaves of Ruellia curviflora typical of species in wet forest habitats. The calyx reminds me of Ruellia glischrocalyx but is not glandular like the latter. Is that comparison so wrong?

Wild collected, Brazil, Erin Tripp #5891, w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Cíntia Kameyama

Ruellia costata

Ruellia costata is one of the many species that have perplexed me for over a decade, and it might have remained as such had we not punched it west towards Mato Grosso near the end of our Brazil fieldtrip (I love your enthusiasm for life, Nico!!!). Not far from Reserva Biológica da Serra Dourada, we found Ruellia costata. It wasn’t in flower, but its vegetative and fruiting morphology readily confirm it to species. Note the extremely long peduncles… typical of many species in the Physiruellia clade.

I feel so fortunate to be alive and experiencing the incredible world of Ruellia diversity.

Wild collected, Brazil, Erin Tripp #5952, w/ Nico Medina (COLO); Photos by Erin Tripp

Ruellia capitata

Deep into that darkness peering, long I stood there wondering, fearing,

Doubting, dreaming dreams no mortal ever dared to dream before….

This is the stuff dreams are made of. The last 24 hrs in Brazil were some of my best on this planet. Nico and I had been driving like maniacs. We had one week remaining and so we punched it out to Mato Grosso to catch the edge of Amazonian botany. Returned via Tocantins and northern Goiás (one long, scary, risky day that we barely survived… but did; ask us in person). We drove late into the night to arrive at the town of Niquelandia, in hopes of searching for Ruellia capitata in the earliest of morning hours prior to driving to Brasilia to catch our afternoon flights.

And that we did – without a moment to waste, we rose at 5am, located the population, and studied hummingbird pollination of its flowers, all before the sun rose.

Ruellia capitata is a highly restricted-endemic species of Niquelandia and immediate surroundings. It is known from fewer than 10 collections, all of them within an area that is probably less than 10 square miles. How is this even possible? In this case, I do not think collector bias is to blame (i.e., the restricted-endemic nature of Ruellia capitata is almost certainly real). One possibility is neoendemism. With each field trip I take, I learn something new and important about how Ruellia species so love metal and cation-rich substrates. I think there is a lot more going on with edaphic specialization in this genus that I previously gave credit to. Another hypothesis to test.

Ruellia capitata is a remarkable species – I do not yet know what it is related to but whatever the sister species, she is a lucky one. One final comment – Ruellia capitata produces the most interesting floral color. Nearly red as in pelargonidin red, but not quite – there is a tinge of something else happening… burgundy-esque. I can’t wait to ask the HPLC for an answer.

Wild collected, Brazil, Erin Tripp #5968 w/ Nico Medina (COLO); Photos by Erin Tripp

Ruellia bahiensis

No matter how far you travel from home, a purple Ruellia is always nearby. Here is one of the many ‘LPJs’ (little purple jobs) that I have the joy of trying to understand. I must add: no matter how boring Lucinda thinks LJPs are, they are fascinating from a floral morphological evolutionary perspective. Time and again, no matter which clade you hone in on, they seem to give rise to lineages with wildly diverse corolla shapes. That is, something about the genetic architecture that underlies LPJ is diverse and ‘creative’ enough to yield all kinds of evolutionarily downstream novelties… but not the other way around.

The native habitat of Ruellia bahiensis in the cerrado leads me to predict this species will be resolved in the Ruellia geminiflora clade along with Ruellia bulbifera and others, but time will tell. For now, sit back and enjoy the story that unfolds…almost as exciting as duet male calling of the black-capped Donacobius.

Wild collected, Brazil, Erin Tripp #5896 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Cíntia Kameyama

Ruellia asperula


Plants like this make you wish you were a hummingbird. Aside from that option, I reckon a botanist was the next best incarnation.

Ruellia asperula is one of the many reasons why the R. inundata clade is simply the genus at its finest. And it is the only member of this clade with bright red flowers (elsewhere: purple, pink, yellow, but never solid red). Ruellia asperula inhabits the dry caatingas of northeastern Brazil and occurs absolutely nowhere else on Earth. Check out some of that scrubby dry forest in the background of these photos.

I might secretly like this species *almost* as much as Roger Federer.

Wild collected, Brazil, N. Medina # 967 w/ E. Tripp; Photos by N. Medina

Ruellia angustior

I am still trying to sort through the correct name of this species (forgive me: it’s true I don’t have all 400 species figured out quite yet. Touché!). For now, I’m calling it Ruellia angustior. Regardless of such a minor point, this was a remarkable plant that we encountered in the campos rupestres and cerrados of Goiás, Brazil, where it turned out to be NOT uncommon, but not frequent.

Unique among this species compared to all others I have learned and studied in the field is that, as the corolla senesces, it separates / breaks apart near that halfway mark of the narrow unexpanded portion of the tube. The lower half stays attached to and envelopes the ovary through fruit maturation. Perhaps some sort of adaptation against seed predation? Incidentally, finding fruits that are entirely predated by small maggots and finding whole populations infected by said seed predators is rampant among Neotropical Ruellia and makes me sad (it’s true)!

Wild collected, Brazil, Erin Tripp #5926, #5929, & #5935 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp, Nico Medina