What Plants Talk About

Lacking eyes, ears, and a brain, plants should—in theory—have no inner life or social side. However, recent research indicates that plants do indeed exhibit elaborate behavior, both above and below ground. Like the rest of us, plants have a constant need for food and nutrients, or they cannot survive. Filmmaker Erna Buffie's PBS-aired Nature documentary sheds light on the little understood world of plants. Plants can engage in foraging activities, putting out scents to attract pollinators, and even emitting "cries" for help, using scents to attract "insect mercenaries" to attack other invading insects (one particularly cunning plant offers an "evil lollipop" that makes the bug smell). Many plants compete for food and territory, illustrated by the dodder vine that—seen in the lab—weaves about snake-like, as it makes its choice about which host plant it will target and attach to for its nutrients. Competition has real world consequences, as in Montana, where the beautiful but alien knapweed is crowding out native grasses, depriving cattle of food, and threatening the livelihood of ranchers. Scientists have also found that plants are capable of "kin recognition": in Canada the ancient Douglas fir acts as a "mother tree" (as in the film Avatar), nurturing younger trees in the forest by an underground network of roots and fungi. While more research needs to be done, the scientists here persuasively argue that plants are more intelligent than we give them credit for. Sure to be appreciated by armchair botanists and nature lovers, this is recommended. Aud: H, C, P. (S. Rees)