Fritillaria delavayi grows on the rocky alpine slopes of China’s Hengduan Mountains, and for more than 2,000 years its dried bulbs have been used to treat heart and lung ailments. Historically, the plant was not hard to find—a bright sprig of green amid a sea of gray scree—but demand for the powder made from its bulbs has made it rarer and more expensive. A kilogram of the powder now costs $480 ($218 per pound), and requires harvesting more than 3,500 individual plants, which only begin to flower in their fifth season, according to Science News.
But just as many animals have evolved camouflage to better evade predators, human harvesting behaviors have spurred many Fritillaria plants to shift from loud greens to the muted grays and browns of the rocks they grow between, the researchers report in a study published [November 20] in the journal Current Biology.
“Like other camouflaged plants we have studied, we thought the evolution of camouflage of this fritillary had been driven by herbivores, but we didn’t find such animals,” says Yang Niu, a botanist at the Kunming Institute of Botany and co-author of the study, in a statement. “Then we realized humans could be the reason.”