Volvariella volvacea, the paddy straw mushroom, is a medium-sized mushroom with a distinctive volva at the base, grey-brown cap, and pink gills arising from free cultivation in tropical Asia for millennia. It grows on rice straw, compost, and decaying plant matter in tropical and subtropical regions of Southeast and East Asia. This saprotrophic fungus decomposes agricultural residues, particularly rice straw, and is widely cultivated as a food mushroom.