What is "arbutoideae"

The Arbutoideae are a subfamily in the flowering plant family Ericaceae. Phylogenetic analysis supported all genera of the subfamily as monophyletic, except Arbutus. Moreover, it was suggested that the non-sister relationship between Mediterranean and North American species may be explained by a once widespread distribution in the Northern hemisphere before the Neogene.

The genera Arbutus, Arctostaphylos, Comarostaphylis form a particular type of mycorrhizal symbiosis with fungi resembling ectomycorrhizas; it is termed arbutoid mycorrhiza.