One of the world’s leading lichen experts unravels the mysteries of a complex life form (and gives them wacky names).
Warty Warts. Powdered Ruffles. Lipstick Powderhorn.
All are species of lichen found in Philadelphia’s Fairmount Park and named by James Lendemer C’06, the curator of botany at the New York State Museum and an adjunct assistant professor at the City University of New York.
One of the world’s leading experts on this 500-million-year-old life form, the Philadelphia native has discovered more than 150 new species as part of his mission to explore their diversity and raise awareness for their protection.
“He’s a leader in the field, a dynamo with a laser focus,” says lichenologist Troy McMullin, the head of botany at the Canadian Museum of Nature.
Lendemer has trekked from the Yukon tundra to Tasmania’s forests to North Carolina swamps to hunt lichens and study how air pollution has decimated their numbers—especially in much of the eastern US, where by the late 20th century lichens had virtually disappeared from many of the landscapes they once blanketed.
“Lichens are miniature universes. They are better thought of as tiny ecosystems rather than strict symbioses,” writes Lendemer, 39, in his book Urban Lichens: A Field Guide for Northeastern North America.
Neither plant or animal, they are not one organism but two—an “intensive cooperation” between a fungus, an algae, and sometimes a cyanobacterium as well. Lichens were among the first living things to gain a foothold on land. Although they survive in extreme desert and mountaintop environments and even exposure in outer space, they respond far less well to human activity and are sensitive to acid rain and sulfur dioxide in leaded gas.
Two hundred years ago Philadelphians would have seen not just smatterings of lichen but a wide array blanketing tree bark, splattered on rocks, painting bricks, and adorning shrubs. Smog wiped out as many as 90 percent of species in the city. Today half of those may have returned but in a modest way, according to Lendemer. Despite this environmental onslaught, only one species of the 5,500 in the US and Canada has been declared extinct. Only two are listed as threatened or endangered by the US government.
“I’m hopeful from the standpoint that things have begun to recover, but I also recognize that their scale of recovery is so long, that is never going to happen in the span of any of our lifetimes,” says Lendemer, who recently served as the associate curator at the New York Botanical Garden where he oversaw its collection of 350,000 lichen specimens, the largest in the western hemisphere.
Lendemer’s love affair with his clingy subject matter began when he was a teen. The Philadelphia native volunteered at the Academy of Natural Sciences, and its botany curator had him organize the institution’s lichen specimens. He majored in biology at Penn, where Hermann Pfefferkorn, professor emeritus of geology, and Ann Rhoads, the former senior botanist at the Morris Arboretum, supported his growing interest.
Such was Lendemer’s passion that while an undergrad at age 19 in 2004 he started the academic journal Opuscula Philolichenum to explore all things lichen related.
“Once I started looking for them in the outdoors, it was like, ‘Oh, these are clearly amazing.’ They were so bizarre and unlike everything else, it was hard to not want to know more about them,” he says. “Everything about them requires you to think about life in a different way.
“They defy so many basic concepts and ways we think about biology and nature. At the same time, they weave together a lot of themes we think of in society and culture. Lichens form this whole that looks nothing like their constituent parts, and the parts can’t survive on their own so far as we know. They live together and form this complex, interdependent relationship. It’s like how one person can’t build a building, but a group of people can.”
Lendemer sometimes fields queries from gardeners worried that lichens can kill plants. “People tend to see them more when they look at trees and shrubs that are sick and dying, because maybe they weren’t looking so closely before,” he says. But in reality, lichens help trees thrive. They absorb moisture like sponges from the air and funnel it towards trees’ roots to help them stay moist. Lichens also allow seeds to germinate, provide food for a host of animals including caribou, and offer nesting material for birds.
These rootless wonders also benefit people. Usnic acid, a natural antibacterial compound found in lichens, is used in natural toothpaste and deodorant, and lichens produce antimicrobial and antifungal chemicals found nowhere else in the natural world. Research into creating biosynthetic versions of lichen has been stymied because they resist growing in labs. The group of lichen species Lecanora esculenta may have even been the manna from heaven that fed Moses and the Israelites in the Sinai after their exodus from Egypt.
Ten years ago, Lendemer co-led the largest lichen survey in US history. The National Science Foundation-funded undertaking enabled him and other researchers to collect 17,000 specimens from 214 sites around the country.
After realizing that scientists had rarely looked for lichen in marshy coastal areas, he soon found himself calf-deep in muddy water in North Carolina’s Bull Neck Swamp. “These areas were amazingly diverse, but they’re imperiled,” says Lendemer. “The need for conservation became so clear during that project, because all of those few remaining coastal places are imminently being lost to sea level rise, saltwater intrusion, and habitat destruction.”
His favorite hunting grounds are in Great Smoky Mountains National Park, where he’s visited annually for the past 15 years and often spots hundreds of species a day. A hot spot for lichens, the Smokies’ moist terrain was never glaciated and has a central area of undisturbed old-growth forest. “He’s discovered a niche where he can make a huge number of contributions on many different levels,” says Paul Super, the National Parks Service research coordinator for the Smokies. “It’s a great place for someone with his energy,”
Lendemer hits the trails in running shoes carrying a five-pound rock hammer, rock and wood chisels, clippers, paper bags for sample storage, and a hand lens. These routes are perfect places for him to spot hitherto undescribed species.
He immortalizes them with arresting names like Unrequited Love, Mexican Sunshine, Four-Spore and Seven Xanthones Ago, I Could Play Tennis Wearing That, Paul’s Super Lichen!, and one he officially dubbed Japewiella dollypartoniana after the country music star who grew up nearby.
Lendemer claims not to have a favorite lichen. “You can’t focus on one lichen, because everywhere you go there’s something delightful. It’s like seeing old friends.
“I love seeing several specific populations over and over again that have been growing on rocks I’ve been looking at for years. There’s something nice about walking by, recognizing they’re still there, and seeing how they’ve changed, if at all.”