MORPHOLOGICAL, CYTOCHEMICAL, AND ONTOGENIC CHARACTERISTICS OF A NEW SPECIES OF VESICULAR ARBUSCULAR MYCORRHIZAL FUNGUS

The new species of endomycorrhizal fungus Glomus coronatum Giovannetti is described using morphological, cytochemical, and ontogenetic characters. Spores are yellow-orange to red-brown, globose, with a hyaline outer wall layer expanding into roughened, flamelike columns in acidic mountants. Sporocarps are formed by the growth of fine hyphal branches from the subtending hyphae, which gradually cover the original spore. Many of the spores enveloped in the hyphal mantle are formed simultaneously and coalesce to form the sporocarp. The importance of the ontogeny of spores and sporocarps in the description of new taxa is discussed.