Myrmecophytes

Myrmecophyte (mər′mek•ə‚fīt; literally "ant-plant") is a plant that lives in a mutualistic association with a colony of ants. There are over 100 different genera of myrmecophytes. These plants possess structural adaptations that provide ants with food and/or shelter. These specialized structures include domatia, food bodies, and extrafloral nectaries. In exchange for food and shelter, ants aid the myrmecophyte in pollination, seed dispersal, gathering of essential nutrients, and/or defense. Specifically, domatia adapted to ants may be called myrmecodomatia.

Myrmecophytes share a mutualistic relationship with ants, benefiting both the plants and ants. This association may be either facultative or obligate.

In obligate mutualisms, both of the organisms involved are interdependent; they cannot survive on their own. An example of this type of mutualism can be found in the Macaranga genus of plants. All species of this genus provide food for ants in various forms, but only the obligate species produce domatia. Some of the most common species of myrmecophytic Macaranga interact with ants in the Crematogaster genus. C. borneensis have been found to be completely dependent on its partner plant, not being able to survive without the provided nesting spaces and food bodies. In laboratory tests, the worker ants did not survive away from the plants, and in their natural habitat they were never found anywhere else.

Facultative mutualism is a type of relationship where the survival of both parties (plant and ants, in this instance), is not dependent upon the interaction. Both organisms can survive without the other species. Facultative mutualisms most often occur in plants that have extrafloral nectaries but no other specialized structures for the ants. These non-exclusive nectaries allow a variety of animal species to interact with the plant. Facultative relationships can also develop between non-native plant and ant species, where co-evolution has not occurred. For example, Old World legumes that were introduced to North America can be protected by ants that originated from a different region.

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