Pacific madrone (Arbutus menziesii) ectendomycorrhizae synthesized in pure culture with Thelephora terrestris, Corticium bicolor, Cenococcum graniforme and Pisolithus tinctorius are described. It is suggested that most arbutoid mycorrhizae of Pacific madrone and other ericaceous plants are formed by the same fungi which are associated with ectomycorrhizae of forest trees.