Glomus gibbosum, a new species from Poland

Glomus gibbosum sp. nov. is described and illustrated. This fungus was found associated with roots of different plants colonizing maritime sand dunes adjacent to Świnoujście in northwestern Poland. Spores of G. gibbosum occur singly in the soil, rarely in loose aggregates or in sporocarps. The globose to ovoid sporocarps contain from 2 to 8 spores enclosed by a common hyphal mantle without an opening. Spores are hyaline to light yellow, globose to subglobose, (70-) 93-115 (-140) μm diam or ovoid to pyriform, 90-110 × 110-170 μm. Spores have one wall composed of five tightly adherent layers: a sloughing, hyaline outermost layer 1, a rigid, hyaline to light yellow layer 2, a laminated, hyaline layer 3, and two thin, flexible layers 4 and 5. Glomus gibbosum produced spores and vesicular-arbuscular mycorrhizae in single-species pot cultures with Plantago lanceolata and Sorghum vulgare.