Texas Parks & Wildlife Magazine   

Archives

February 2009 cover image of Davis Mountains State Park

Flora Fact : Lichen Lore

Lichens have been used since ancient times for dyes and medicinal teas.

By Sheryl Smith-Rodgers

So when’s the last time you stopped to admire a lichen? Not lately, eh? Don’t feel bad. Most folks haven’t either. Meet an exception: Taylor Quedensley, a plant biology graduate student who’s accumulated more than 8,000 specimens.

“I find lichens fascinating,” he says. “In the tropics, up to 40 species of lichen may occur on one small leaf.” In his free time, the Austin resident frequents the Balcones Canyonlands National Wildlife Refuge, where he searches for lichens on tree bark, rocks, limestone cliffs and soil.

Simply put, two organisms — a fungus and an algae — form a lichen. As a team, the fungus supplies the dominant structure (called a thallus) while the algae produces food via photosynthesis. That said, lichens are generally classified by shape: fruticose (shrubby or hair-like), foliose (leafy or ruffled) and crustose (crust-like). Colors range from dull creams, greens and grays to mustard yellow, blood red, burnt orange and even cobalt blue.

Mostly slow growing, some lichens reproduce by releasing spores. Others spread by broken fragments that attach to a new substrate. What’s their purpose in nature? “They function like leaves by producing oxygen,” Quedensley says. “They also break down rocks to create soil.”

Both humans and animals use lichens. For instance, people have boiled and fermented lichens since ancient times to create dyes, drugs and medicinal teas. Caribou and reindeer rely on lichens for their winter diet. Factoid: Beatrix Potter — before she penned her many famous children’s books — studied fungi and lichens.

back to top ^