A new species of the Glomeromycetes is diagnosed by bright yellow to dark yellow bi-walled spores (85-131 mu m diam.) that form terminally on cylindrical subtending hyphae. The yellow outer spore wall is continuous with the hyphal wall, while the germ tubes emerge during germination from the hyaline inner wall to penetrate the outer wall. Phylogenetic analyses place the new fungus, Corymbiglomus pacificum, within the Diversisporales next to C. corymbiforme and C. globiferum. The new species was found in the Araucan a region of southern Chile in the rhizospheric soils of Ammophila arenaria at the mouth of Lake Budi, a saline ecosystem where the lake is periodically directly connected to the Pacific Ocean.