Root morphology, anatomy and mycotrophy of the achlorophyllous Voyria aphylla (Jacq.) Pers. (Gentianaceae)

Roots of Voyria aphylla only develop hairs where roots of neighboring plant s or organic litter are attached. Fungal penetration occurs almost exclusiv ely at these root-to-root attachments, The ecological significance of these immediate hyphal bridges for achlorophyllous plants is discussed. The morp hological and anatomical features of V. aphylla roots and its Paris-type ar buscular mycorrhiza (AM) appear to be transitional between those of V. trun cata and V. tenella, A hypothetical evolutionary progression of AM and its significance for the development of mycoheterotrophy is proposed,