Glomus candidum, a new species of arbuscular mycorrhizal fungi from North American grassland

A new species of arbuscular mycorrhizal fungi, Glomus candidum is described. The species produces spores singly in the soil. Spores are white to very pale yellow, usually globose to subglobose, 87-157 μm diam. Spore wall consists of two adherent layers. The outer layer is hyaline, mucilaginous, and stains very pale pink in Melzer's reagent. This layer can be observed in young spores and often degrades at maturity. The inner layer is hyaline and laminated, but occasionally the innermost group of laminae are pigmented a pale yellow to give the impression of two separated layers.