Plants that make active decisions? Read more in the Early View paper “Informed dispersal in plants: Heterosperma pinnatum (Asteraceae) adjusts its dispersal mode to escape from competition and water stress” by Carlos Martorell and Marcella Martinez-Lopez. Here’s their summary of the paper:
We all know someone who has migrated to a wealthy country because social or economic conditions in her/his homeland are harsh. Among animals the same phenomenon occurs, sometimes taking the form of huge migrations away from areas that are seasonally adverse because they are too cold or too dry. But what about plants? We all know that plants can move from one place into another when they are seeds, but it would appear that they are unable of judging whether it is profitable to stay in their natal site or to migrate in search of a better place. To do so, plants, like animals, need to gather and process information about their environment. The small annual plant Heterosperma pinnatum does exactly so. When the environment in which it grows is too dry, it promotes the long-distance dispersal of its seeds. The same happens in crowded areas where competition for the available resources is strong. In this way, its descendants may find more favorable places to live in. The mechanism is quite simple: H. pinnatum produces two different kinds of fruit, one that has hooks that become attached to animal fur and thus can travel very large distances, and another kind that lacks dispersal structures and thus remains in the close vicinity of the mother plant. By regulating the proportion of each type of fruit depending on environmental conditions, this plant is able to decide whether its descendants will continue to exploit the local resources or else face the risks of long-distance travel in search for a place where they may have better chances to survive and reproduce.