Volvariella surrecta
English: Piggyback rosegill; Button mushroom.
Synonyme: Agaricus surrectus; Agaricus loveianus; Volvariopsis loweiana.
Name: surrecta is Latin for "to arise".
German: Scheidlinge.
Region: Asia, North America, Northern Africa, Europe, and New Zealand.
Content: agaritine, a carcinogenic hydrazine.
Use: inedible.
Mycology
This species is parasitic on Clitocybe nebularis. It is rare, but widely distributed. They have white or greyish silky-hairy caps up to 8 cm in diameter, and white gills that turns pink in maturity. The cap surface is dry and covered with long, silky hairs; the color is white to light gray, with a yellowish or brownish center. The gills are free from attachment to the stipe and are packed close together. They are initially white, later becoming pink. There are many lamellulae, short gills, interspersed between the gills. The stipe is white, is up to 9 cm long, roughly equal in width or somewhat thicker at the base, white to light gray, the surface is appresse, fibrillose, with a pruinose coating near the apex. The white volva measures ± 2 cm high and ± 1cm broad, with a lobed margin. The spore print is brownish-pink. The spores are egg-shaped to oval.