Published: Dec. 1, 2015 By

Erin Tripp

Lichen Hunter

(full, unabridged version)

Even amid a massive die-off of life on Earth that’s been called “the sixth extinction,” scientists continue to discover new species. CU-Boulder biologist Erin Tripp recently found two previously unknown species of lichens — in the same location in the same week. She was participating in a joint lichen inventory at Boulder’s White Rocks Nature Preserve with the City of Boulder’s Open Space and Mountain Parks Program.

Can we safely say you were pleased?

Of course I was pleased! But then again, I am always pleased when I’m in the field collecting lichens or plants. Life really doesn’t get any better than spending a day with “endless forms, most beautiful” (Darwin’s words). Biologists create our own adventure, and lichens make this especially memorable!

How did these lichens catch your eye?

Finding new species requires both keen observation as well as good luck. They say that a typical taxonomist sees 40% more of his or her surroundings than all other human beings. OK, fine — I can have the best set of lichen eyes in the world, but it wouldn’t matter if I were in the wrong place. Chance had it that the first rock I wandered towards at White Rocks Open Space (Boulder, Colorado) hosted a very curious lichen with a thick white thallus and raised, black fruiting bodies. From about five feet away, I immediately honed in on this curiosity, and proceeded to make my first collection. At a later hour, I happened to pause near the edge of the sandstone formation while my graduate student Vanessa Díaz was photographing a Xanthoparmelia. While waiting for her to finish, and yawning in the heat of an August morning in the plains, I glanced down between my feet and noticed a beautiful crustose species with a chartreuse thallus whose identity was unknown to me. I suspected both were special, perhaps unknown to science, and I was right. It’s just the way that it goes!

What is a lichen, by the way?

A lichen is an obligate symbiotic relationship between a minimum of two unrelated an organisms, primarily a fungus and a green alga (or a cyanobacterium). But lichens often host a diversity of other organisms too — they’re a microcosm and a source for evolutionary innovation. Lichens are most commonly confused with mosses or other bryophytes, but with just a little practice, an amateur can easily learn to identify lichens. For starters, google them! Or better yet, grab a field guide and go for a hike in the mountains or the plains and try to find them. This won’t be hard: In Colorado, lichens are everywhere. Amateurs wanting to see and learn more lichens can also read Irwin Brodo et al.’s Lichens of North America, a beautiful coffee table book. Alternatively, you will soon be able to purchase a copy of my Field Guide To The Lichens Of White Rocks Open Space(Boulder, Colorado), which is currently in press at the University Press of Colorado.

How did you determine the lichens you found were new species?

Finding new species of anything biological comes with several pre-requisites, in particular: a long history of studying a group of organisms in detail, hence taxonomic expertise and sufficient knowledge of, and comfort with, the primary scientific literature. This is called ‘taxonomic expertise.’ Reaching a point where one feels confident enough to describe a new species is by no means a trivial process: It takes a lot of work, a lot of experience, a lot of grit, and a lot of drive to learn and keep learning. None of those things can ever be compromised.

Are there lots of species?

There are about 20,000 named lichens in the world… thousands more to be described, for sure. No lichenologist has ever fully treated the lichens of Colorado, but my guess is that there are 1,000 to 1,500 species present in the state. Give me another 25 years and I might have a better answer for you. Better yet, give me a grant or a contract of sufficient magnitude and I’ll have you an answer within 15!

How did you get interested in them?

I was first turned on by lichens while working on my undergraduate degree (biology, with an emphasis in botany) at the University of North Carolina-Asheville. I am a huge fan of the southern Appalachians, a refuge for biodiversity and general happiness in North America, as far as I am concerned. Take a walk through any forest in the southern Apps. Need some further direction? Head straight to Great Smoky Mountains National Park. Step out of the car and be instantly overwhelmed and smitten. Lichens are everywhere and abundant in that part of the world. One cannot help but notice them and wonder about them (and maybe try to strike up a conversation with them). With a bit of digging around, one quickly learns that lichens are majorly understudied and underappreciated. And at that point, it was a matter of minutes before falling in love. A decade (and a lot of field work, herbarium work, and collection of voucher specimens) elapsed before we eventually synthesized what we had learned about the lichens of this region (see our book: The Lichens And Allied Fungi Of Great Smoky Mountains National Park, New York Botanical Garden Press). Lucky for us here locally, lichens are also extremely diverse and abundant in Colorado. Curiously, given the general awesomeness of our state, lichens are perhaps more poorly understood in Colorado than they are in just about any other state in the USA. Needless to say, Colorado is going to yield a lot of new discoveries once our lichen biota is further researched. I should note that discoveries are, of course, one thing, new and exciting. But the evolutionary histories of each and every one of these new species is even more exciting….

Tell us more about these newest lichens. What did you name them and how did you pick the names?

Gosh, the names came to me almost instantaneously! I named Lecidea hoganii after Tim Hogan and Candelariella clarkiae after Dina Clark. Tim and Dina are the two Collections Managers of the University of Colorado Herbarium, which is a tremendously important plant natural history collection of >500,000 objects that are part of University’s Museum of Natural History. Tim and Dina are expert Colorado botanists who have devoted their careers to building knowledge of and conserving the rich heritage of Colorado botany. I wanted to say thanks to these two BCMEs (Best Collections Managers Ever) and did so by honoring them with names for the new species. The new Lecidea is ‘dark and complex, but a little rosy on the inside’, sort of like Tim’s personality, whereas the new Candelariella is ‘bright and sunny, just like Dina’s disposition’. You can read more about the eponomy in the publication of these new species by myself and colleague James Lendemer in the journal The Bryologist. As far as museums go, and no matter what institution we are speaking of in whatever locality, collections managers are some of the most important employees. My hope is that the above actions serve to call attention to the important contributions that they make to natural history museums worldwide.

And what did you do with the new ones you found?

I invited them over to dinner, naturally, and after a nice meal and glass of wine, I did with them what all taxonomists do with new species: I accessioned them into our museum, and filed them in an expensive, protective, long term storage case. In it, they will ‘live’ comfortably in perpetuity with other ‘type specimens’ — specimens that are selected to serve as a reference point of sorts for the species being named. In 150 years from now, the Colorado Herbarium collections managers will pull these ‘type specimens’ out of the cabinet and tell the story I am telling you now, perhaps with embellishment, perhaps without, but always with a sense of reverence of the history that precedes us. What would we be without history?

How has the scientific community responded to your discovery?

Well, the manuscript (to be published in The Bryologist) has not yet been printed, so the official word isn’t yet out, but with the release of the online article I have received a lot of positive feedback about the general inventory work at the sandstone formation as well as further curiosity about the new species. We here in Boulder are very fortunate to live in a city that values and protects its open space. I am indebted to Boulder’s Open Space and Mountain Parks Program, and awesome staff ecologists such as Lynn Riedel and Megan Bowes that make the program hum along. In fact, a big shout out to green space preservation programs and their staff nationwide.

You said there are many other lichen species awaiting discovery…

Absolutely and without doubt! There are appallingly few scientists who are actively working on (and know) lichens in various parts of the world. Here in western North America, I can count those individuals on one hand. Such a small number of practicing professionals makes for slow progress, but also high potential for discovery. Colleague James Lendemer and I have already described numerous new species to science as part of our lichen work in the southern Appalachians, with many more left to discover and describe. I predict no fewer than 50 (and probably closer to 100) species of lichens new to science right here in Colorado, but we’ve got to do the work first, which requires writing and re-writing a lot of literature along the way!

How do you keep yourself busy when you’re not hunting for lichens?

Two words: assistant professor. Nearly every 15 minute block of my typical weekday is accounted for, as are often my nights and weekends. University life is dizzying at times, but also rewarding: Academic freedom is truly exciting and inspiring and I am grateful for every moment of it (well, most moments anyway). When I can piece together time to do other things, it usually involves trail runners, topo maps, benchmarks, racquets, power tools, binoculars, derailleurs, pressure cookers, or some really, really great lines of poetry.

Photo by Patrick Campbell