 The thick, unbranched stems are covered in clypeoli and alveoli which also grow spines and are densely filled with dry bracts.They form a symbiotic relationship with ants and fungi; "Philidris cordata" (formally "Iridomyrmex cordatus") is believed to be the most common ant found occupying "Myrmecodia" species.Ant plants provide habitats for ant colonies high up into the forest canopy, protecting them from the elements, and in exchange, the nutrients from the ants and the debris left by the ants be absorbed in the plant's chambers.