That the symbiotic fungus of leaf-cutting ants only occasionally produces the sexual phase makes their identification confusing. This
has occurred so rarely, either in laboratory nests, or in unbalanced field nests, that the possibility of contamination of the fungal
garden by other fungi cannot be disregarded. In this paper we describe the formation of several basidiomata in a healthy and free-living nest of the leaf-cutting ant Acromyrmex hispidus fallax, the cultivation in vitro of the sterile mycelia (isolated from the fungal
garden) with their typical inflated tips, and the similarity of both forms confirmed by RAPD analysis of their genomic DNA. The
fungus was identified as Leucoagaricus gongylophorus.