Animals in the wild have many ways of warding off predators.  Whether they warn predators through bright coloration, escape danger by changing locations, or use camouflage to blend into their environment, animals seem to have better alternatives than plants to avoid predation.   Since plants are grounded in one place, how do they escape from danger?

Because plants use their bright coloration to acquire food through photosynthesis or to attract pollinators, camouflage in plants seems to be unwarranted.  However, a recent study by Matthew Klooster from Harvard University uncovers that the woodland plant, Monotropsis odorata, might have adapted its own camouflage, much like animals, to avoid predation.

Instead of performing photosynthesis to obtain nutrients, this woodland plant species actually relies on mycorrhizal fungus that resides within its roots for nutrition.  As a result, the plant no longer needs green coloration necessary for photosynthesis.  Brown colored bracts grow around the reproductive stem and flower.  Klooster discovered that these bracts function as a camouflage and help the plant blend in with its surroundings.

The bracts on the plant resemble leaf litter and conceal the deep purple reproductive stem, as well as the lavender buds.  By removing dried bracts from some plants, the research team concluded that the bracts actually increase plant fitness by helping the plant avoid predation by herbivores.

Because the Monotropoideae continue to rely on animals for pollination and seed dispersal, the researchers hypothesize that the flowers emit highly fragrant odors that will attract pollinators and allow for reproduction of the plant.

Therefore, next time you’re in the woods and assume that a brown plant must be a dead plant, think again!

Discussion Question: Why do you think that more plants have not evolved a camouflage system?  What type of environment would make camouflage in a plant necessary?

[Enjoyed this story?  Check out another story about plant camouflage in our archives.]

Link to News Article: http://www.sciencedaily.com/releases/2009/11/091125145825.htm
Link to Journal Abstract: http://www.amjbot.org/cgi/reprint/ajb.0900124v1