September 29, 2009

Ant Plant

Myrmecodia platytyreaThe genus name Myrmecodia is derived from the Greek myrmekodes, meaning ant-like or full of ants.  Myrmecodia is native to Northwest coast of Borneo, East Malaysia, New Guinea, and North Australia, Myrmecodia platytyria grows in tree branches and on trunks.  It develops a grotesque, somewhat spiny tuber at its base that  helps it form a symbiotic relationship with ants.  The tissue inside this specialized organ dies off in such a way as to form chambers and small airways for ventilation, providing an ideal habit to house ant colonies. But this is not a free ride for the ants; either by dying or defecating they bring nutrients to the plant, helping it to grow.

(top) Myrmecodia  platytyria on display in the Tropical Greenhouse. (bottom) Cutaway view of a Myrmecodia tuber showing chambers
drawing courtesy of

 
It is thought that the established ant colony also helps to protect the plant from insects, but there are conflicting studies.  One study looking at another type of ant plant in the Amazon found that after removing ants, the plant was 4.3 times more likely to have herbivorous (plant eating) insects on them compared to plants with ants; however a University of Connecticut study found that ant-plants are more susceptible to a number of common pests such as scale and mealy bugs because of the ants behavior of ‘farming’ these pests on the plants that host them. The Arboretum has a Myrmecodia platytyria on display in the Tropical Greenhouse.