From The Daily Galaxy:
Plant "IM"—Scientists Begin to Unravel the Secret Communication of the Green Kingdom
For most of history scientists and mankind in general considered plants to be passive organisms just with no reason or means of communicating with one another. But new research has revealed that many plants actually ‘chat’ quite a bit over their own networks, which may also indicate that your aunt isn’t quite as crazy as you thought. You know, the one that talks to her petunias and expects an answer.
Researcher Josef Stuefer at the Radboud University Nijmegen found that one purpose for plants having their own “chat systems” is to warn each other, leading scientists to conclude that plants are not quite as boring as once supposed. In fact, many plants form internal communications networks and are able to exchange information efficiently. Herbal plants such as strawberry, clover, reed and ground elder naturally form networks. Individual plants remain connected with each other for a certain period of time by means of runners. These connections enable the plants to share information via internal channels in a manner very similar to computer networks. So what kind of things do plants tell each other?
Stuefer and his colleagues were the first to demonstrate that clover plants do indeed warn each other via these network links if enemies are nearby. For example, if one of the plants is attacked by caterpillars, it will warn the other members of the network via an internal signal. After receiving a warning, the other intact plants will strengthen their protective chemical and mechanical resistance so that they are less attractive for advancing caterpillars. This early warning system allows the plants to stay one step ahead of their enemies. Experimental research has revealed that this communication significantly limits the damage to the plants.
It is also known that plants have “family values”, with new research revealing they have the ability to recognize close relatives in order to help each other survive. The ability to tell family from strangers is well known in the animal kingdom, which allows us to cooperate and share resources. However, it is a relatively new concept that plants also possess the social skills of being able to recognize and communicate with relatives. Even plants that are not connected seem to have the ability.
Earlier this year, Susan Dudley and Amanda File of McMaster University in Ontario, Canada, demonstrated for the first time that plants can recognize their kin. Their research showed that though lacking cognition and memory, plants are nonetheless capable of complex social interactions.
"Plants have this kind of hidden but complicated social life," Dudley said.
Their study found plants from the same species of beach-dwelling wildflower, for example, grew aggressively alongside unrelated neighbors but were less competitive when they shared soil with their siblings. Some researchers speculate that plants must communicate through their roots, identifying themselves using tiny chemical signatures specific to each plant's family. But just how the plants determine which of their neighbors are siblings remains a mystery, Dudley said. While learning and memory are important factors for kin recognition in animals, there has to be an alternative explanation for plant recognition, she noted.
This research, along with other emerging plant studies, is revealing that our current concept of plants is probably a poor reflection of reality. Scientists are eager to discover in what ways, and to what extent, plants communicate with each other.