Volvariella surrecta (Piggyback rosegill)
Species: V. surrecta
Binomial name: Volvariella surrecta
Synonyms: Agaricus surrectus, Agaricus loveianus, Volvariopsis loweiana, Volvaria hypopithys subsp. Loveiana, Volvaria surrecta.
Common name: Piggyback rosegill
Volvariella surrecta, commonly known as the piggyback rosegill, is a rare species of an agaric fungus in the family Pluteaceae. Although rare, the species is widely distributed, having been reported from Asia, North America, Northern Africa, Europe, and New Zealand. The fungus grows as a parasite on the fruit bodies of other gilled mushrooms, usually Clitocybe nebularis. Volvariella surrecta mushrooms have white or greyish silky-hairy, convex, caps up to 8 cm in diameter, and white gills that turns pink in maturity. The stipe is, also white and can be up to 9 cm long, and has a sack-like volva at its base.
Volvariella surrecta grows parasitically on the fruit bodies of Clitocybe species, usually C. nebularis, although it has been reported growing on Tricholoma species, as well as Melanoleuca brevipes. The mushrooms grow in clusters, and fruit in the summer and autumn. The host mushroom is sometimes malformed and assumes an irregular appearance. (Wikipedia)