This member of the Ericaceae is responsible for forming arbutoid ectomycorrhizal associations with members of the Agaricales, Boletales, and Russulales. The roots of the plant take on a definitive morphology and anatomy. Above timberline, in the páramo zone of the Talamancas, the plant can form extensive thickets, or in some sites, semi-open mono-dominant stands occur (at left).

A complete description of, and distinction between, the 2 subspecies can be found at J. Luteyn's Neotropical Blueberries site. Both subspecies are shown below and can be distinguished by the presence (subsp. arbutoides) or absence (subsp. costaricensis) of a rusty colored tomentum on the underside of the leaves.