Ruellia sororia

This species is among my top five favorite finds in the field. Prior to our covert operations to relocate a historical population of it (a fieldtrip in which I was accompanied by Carrie Kiel and Kristen Hasenstab-Lehman), it had been collected only twice in history: first in the late 1800s (the type collection), and again in the early 1980s (when it was described under a different name). We found it in an amazing, high quality montane semi-deciduous forest just E of Chilpancingo. Unfortunately, access to this area was recently (2011-ish) made WAY too easy because of construction of a brand new superhighway right through the gut of the region. I fear it is only a matter of time before the forests (and plants such as these) slowly disappear to make room for the strip malls…

Ruellia sororia is member to Ruellia section Chiropterophila, an entire clade of which, at present, is known only from Mexico. Species in section Chiropterophila are for the most part rare or extremely rare (see Tripp 2010, Systematic Botany). Ruellia sororia happens to be endemic to Guerrero. The plant is, among other reasons, remarkable for its morphological intermediacy between two morphological groups within sect. Chiropterophila. It is the only species in the clade that produces those strangely urceolate corollas AND produces flowers in dichasia.

Note the tinges of anthocyanin production in three visible whorls of the flower. This clade is otherwise marked by a complete lack of anthocyanin pigmentation.

Wild collected, Mexico, Tripp et al. #1206 (RSA-POM); Photos by Erin Tripp

Ruellia salviifolius

Every species has a story, and some are easier to learn than others. Somewhere along the 8+ million year history of the lineage that gave rise to Ruellia salviifolius was the evolution of ternate leaves that smell strongly of mint. Just like the bedtime stories you grew up with, in a land far, far away, but written over a much, much longer period of time.

We found this species once and only once during our August 2016 fieldtrip… one of the best months of my life. Where does it ‘go’ phylogenetically? Well, in a clade with its purple-flowered pal, Ruellia incomta, naturally. And a few others, too. Ancestral state reconstructions on our full cerrado dataset will tell if indeed it is plausible that Ruellia verbasicformis, a most remarkable bat-pollinated species with enormous yellow flowers, gave rise to this minty, ternate, red-flowered species….


Wild collected, Brazil, E. Tripp #5925 w/ Nico Medina & Cintia Kameyama (COLO); Photos by Erin Tripp

Ruellia pohlii

Working on such a spectacular group of plants must feel in part like having 400 favorite children to choose from, right? Each day I try to avoid playing the favorites game, but sometimes succumb. For a large portion of our August 2016 fieldtrip in Brazil, Ruellia pohlii was my favorite. We found this absolutely remarkable species in a gorgeous cerrado over sandy soils, 33 km W of Cavalcante headed towards Serra do Tombador. But, wait for it….

THIS SPECIES IS DISTICHOUS!!!! To my knowledge it is the only species with such a growth form in the entire Acanthaceae. I even have a movie of it spinning around, which ought to be X-rated to an Acanth systematist.

In addition to its remarkable growth form, note the diaphanous leaf veins.

Plants were locally common in a small area but not found anywhere else. By its distichous growth form (to about 20 cm tall), its purple corollas, and its narrow leaves, the only name that can possibly be applied to these plants is Ruellia pohlii. Little known, never used, time to resurrect it from the dead. Ruellia species diversity is growing by the day.

Wild collected, Brazil, Erin Tripp #5933 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp & Cíntia Kameyama*

Ruellia pereducta

One of the many reasons I love Chiapas…. yet another endemic / near-endemic to that state. We found Ruellia pereducta near Nuevo Guerrero. Not at all common. We had to work hard for it.

For whatever reason, this part of the world has a bona fide concentration of the dark pink flowered Ruellias… just like Brazil has the mother lode of red ones.  These pink things must be loaded with cyanidin but… you and me and the HPLC: we await the answer.

Precise phylogenetic placement of Ruellia pereducta similarly awaits RADseq results, but it’s in the Physiruellia clade to be sure. Note the winged peduncles and leaves with rounded bases… these features nail down application of the name. Also – the leaf venation is distinctive, at least to me…

Wild Collected, Mexico, Erin Tripp #5744, w/ Manuel Luján & Amanda Fisher (COLO); Photos by Manuel Luján, Erin Tripp

Ruellia ochroleuca

I ought to be fined for waiting so long to write about this species. Or at least given a demerit! Ruellia ochroleuca is one of my true loves. Like all the other species, it comes with a true story.

I first learned of Ruellia standleyi (not a typo, I’m talking about Standley’s Ruellia) as a graduate student. It is a beautiful and unique species with tiny pale, yellow flowers that inhabits mesic, montane forests of Costa Rica and Guatemala. I laid eyes on it during my first field trip to Costa Rica, in 2005.

About that same time, I had been sequencing a bunch of crap from Brazil that I knew next to nothing about. Woke up one spring morning, made coffee in the Manos lab as I always did (yes, I measure my life in coffee spoons), and saw the results: Ruellia standleyi from Costa Rica/Guatemala was, in a phylogeny of 171 species, sister to Ruellia ochroleuca from the Atlantic Forests of Brazil.

I promptly went to check my specimens and the types of both names. They were identical. I managed to keep my coffee in the cup amongst large measures of excitement at a wide disjunction between the wet forests of Central America and coastal Brazil.

Long story short (hey – I’m trying): in 2012, Lucinda and I wrote a manuscript sinking Ruellia standleyi into Ruellia ochroleuca (the latter has priority and, fortunately, has a much better epithet). In August of 2016, some 14 years after I first started studying Ruellia one cold wintery day in downtown Philadelphia, I finally experienced Ruellia ochroleuca in the field. I can confirm that it indeed is conspecific with (or nearly so… with a modicum of molecular divergence) the former Ruellia standleyi. Sorry Standley.

Ruellia ochroleuca is one of many members of the Ruellia inundata clade that I have been dying to study from a corolla color evolution perspective. We now have near complete sampling of this lineage in hand and are primed for the work. Just need to find time!

Wild collected, Brazil, Erin Tripp #5897 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp & Cíntia Kameyama

Ruellia oaxacana


I first saw this species while doing some solo fieldwork in Mexico, at the terminus of an already dark and dreary day. The year: 2005. Not enough sunlight for profound thought or for photography. Nonetheless, I was convinced it was Ruellia metallica and that I was the first human ever to lay eyes on this species in Mexico. It was producing cleistogamous (closed) flowers only…. as sad as is dying of a mexican daylight.

[Time passes…a year later….]

Looking at my collection of this plant more carefully in the herbarium, it seems to consistently have more seeds per fruit and more slender fruits than does R. metallica (which is now affectionately known as R. terminale, thanks to yours truly & friends; see Tripp & McDade 2012, Brittonia). As it turns out, several other collections from this region of southern Mexico also fit this pattern! With some additional research, I decided that these southern Mexican plants should be attributed to Leonard’s infrequently used name, Ruellia oaxacana. Furthermore, this species turns out to be genetically distinct from R. terminale… a question likely to be posed in the next Republican primary.

[Time passes…. 10 years later….]

Yep – I’m still working on Ruellia. Somehow, she let’s me. I feel as lucky as I did on day one. I still remember the first Ruellia I ever saw in the cellulose. The limestone glades near Williamsburg, Pennsylvania. I could barely contain the joy. Still to this day, species number 97 or whatever it is, I can barely contain the joy.

Anyway, Manuel Luján, Amanda Fisher, and I had a most awesome fieldtrip throughout Chiapas and Oaxaca in January 2016. I saw this species again… for the 2nd time… alive and doing quite well. We were about 6.9 km E of the turnoff from Pochutla to Miahuatlán, headed towards Cafetal Concordia. Lovely area, it was. Ruellia oaxacana likes it dank and dark. This population was growing all around the banks of a perennial river and its waterfalls… both unnamed. The mountain’s name? Something about “Ovambo”. It was growing sympatrically with Ruellia stemonacanthoides, for the record. That information is potentially more important than immediately realized.

Just like the first time, the population (rather massive, actually) was reproducing only thru cleistogamous means. Don’t ask me why. I wish I understood the rules of assembly so that I could try them on myself…

Wild collected, Mexico, Tripp #189 (DUKE); Photo by E. Tripp

Wild collected, Mexico, Tripp et al. #5771 (COLO); Photo by M. Luján

[Time passes…. 2 years later….]

Both Victor Steinmann and Tom Daniel have now seen Ruellia oaxacana in flower – lucky for all of us! The two above photos reflect their contributions / donations…

Wild collected, Mexico, Steinmann & Ramirez-Amezcua 6620 (CAS); Photo by V. Steinmann

Wild collected, Mexico, Daniel 11803 (CAS); Photo by T. Daniel

Ruellia nitens

Life was easy in my stupid bliss, back when I only ever knew this species flattened in a herbarium.

Into that desolation of reality: I’ve now seen it in the field, in its many manifestations, and sort of feel like I need to talk to a counselor. Or perhaps try a confession booth.

Sometimes it’s scrambling, sometimes it’s a shrub. You find it purple, you find it yellow, you find it short, you find it tall. See a bit of this variation in the photos.

Nonetheless, Ruellia nitens is relatively distinctive by its small, elliptical, always shiny leaves. The latter trait gives away its identity more than any other.

And, as with several others, “I have no idea where this species goes phylogenetically”. I cannot wait sink these many mysterys into an Illumina lane…

Wild collected, Brazil, Erin Tripp #5916 & #5941 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp

Ruellia neesiana

In the next town forum, I would like to ask 2016 United States presidential candidates Hillary Clinton and Donald Trump what their thoughts are on the distinctiveness of Ruellia neesiana and Ruellia macrantha. When the smarter one replies that she thinks it is primarily the purple vs. pinkish corolla hues as well as allopatry, and the dumber one replies by asking why I talk in italics, I will tell them both that I don’t care about their answers because I SAW RUELLIA NEESIANA MACRANTHA WHATEVER IT IS ALIVE IN THE FIELD AND YOU DIDN’T!!

The long-standing supposed features distinguishing these two entities are, just as The Queen said, corolla color and allopatry. Ruellia neesiana is said to have purple corollas whereas Ruellia macrantha has pink corollas. I have (and Lucinda has) for many years cultivated the latter in my greenhouse (her in her garden), courtesy of some miscellaneous seed catalogue. When I arrived for the first time ever in the native habitat of Ruellia neesiana in August of 2016, I was fully expecting to see very differently pigmented, richly purple corollas. That’s not what I found. Instead, I found a plant that reminded me highly of R. macrantha, albeit a bit more purple. Still, I have yet to see the latter in the field and do not yet have anthocyanin data on both entities, and will withhold final judgment on ‘one vs. two’ until I do.

This species or these species, whatever you prefer, are absolutely unmistakable for anything else in the entire genus because they are the only lineage to have evolved resupinate corollas. Sort of like orchids but WAY more titillating. At first glance, you might confuse this Acanth for a giant Solanum (they bear some similarity), but the latter guess is not in your best interest.

There is a beautiful population of Ruellia neesiana near the ‘town waterfalls’ of Barra do Garças in Mato Grosso. There is a not so beautiful population of this species in a trash pit not far from the border of Parque Estadual Serra dos Pirinos in Goiás.

Wild collected, Brazil, Erin Tripp #5950 & #5957 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp

Ruellia matagalpae

Curiouser and Curiouser! Alice must have been talking about the first time she saw Ruellia matagalpae in the field. A strange bird with a strange flower morphology and color. Its wickedly narrow floral tubes beg butterflies to pay a visit (and had I stopped to ponder longer, I might have an answer for you).

Ruellia matagalpae occurs from Chiapas, southern Mexico to the Cordillera de Guanacaste, extreme northern Costa Rica (see new country record reported in McDade & Tripp 2008, Brittonia), where it inhabits the understories of semi-evergreen forests. Alas, you’ll most likely find plants scrambling up and the meanest, steepest slopes… just like the rest of the genus, and any fine botanist.

Before seeing this species in the cellulose, i.e. based on herbarium specimens, I predicted that this species would be placed phylogenetically proximal to Ruellia yurimaguensis and R. tarapotana (from Peru and western Brazil) as well as R. tubiflora (from northern South America, primarily) based on its ovate to elliptic, greenish-white, leaf-like bracts that subtend the sessile dichasia. Every now and then, I get it right: in Tripp (2007, Systematic Botany), you can see that in fact Ruellia matagalpae is a fairly close relative to these species.

Wild collected, Mexico, Tripp, Lujan, & Fisher #5749 (COLO); Photos by M. Lujan & E. Tripp

Ruellia incomta

Once upon a midnight dreary, while I pondered, weak and weary,

Over many a quaint and curious volume of forgotten lore—

Suddenly there came a tapping….rapping at my chamber door….

Rapping at my door in August of 2016 was a whole new world of Ruellia diversity so massive and magnificent. Ruellia incomta was one of 42 species (!) that we found during our Brazil fieldtrip, making this excursion among the most successful targeting a single genus in history.

Ruellia incomta is highly distinctive and, lucky for me, looks just like it does on a herbarium sheet! It cannot be confused for anything else. Start with those cute, oblanceolate bracts that typify a profusely branching inflorescence. And then note the great density of vegetative glands. BTW: this plant is ALL inflorescence, with very few leaves (I’ve attempted to show you this in the photos).

Ruellia incomta practically shouts its own name in a language I am close to understanding. Look for nice populations of this species near the top of a mountain that immediately borders Barra do Garças (Mato Grosso) to the north.

Wild collected, Brazil, Erin Tripp #5921, 5955, & 5959 w/ Nico Medina, Cíntia Kameyama (COLO); Photos by Erin Tripp, Cíntia Kameyama