Abstract
The dry slopes of mountains in southern California (USA) are often covered by chaparral—dense shrubby vegetation with characteristic plants such as Adenostoma sp., Arctostaphylos sp., and Ceanothus sp. This unique ecosystem is home to a wide array of animal, plant and fungal species, which also show a high degree of endemism. For example, the polypore Phellinus arctostaphyli (Long) Niemelä grows only on the three shrub species mentioned above and is endemic to western North America (Gilbertson & Ryvarden 1987).