In the summer of 1968 I investigated the fungal associations of three species of Corallorhiza which grow in northern Michigan, namely C. trifida Chatelain, C. maculata Raf., and C. striata Lindl. ... All three species of Corallorhiza were found to be able to form an association with more than one species of fungus. This supports the findings of earlier workers for C. innata. ... The orchid, particularly in the case of C. trifida, although obviously obtaining nourishment from the fungus, forms a relatively harmonious association with it, for the infected cells suffer no obvious damage. This situation contrasts with that in some other orchids, such as Gastrodia minor, where the infected region of the tuber ultimately collapses.