Marasmius undatus (Berk.) Fr. syn. M. chordalis Fr. Saiten-Schwindling. Cap 1–2cm across, convex, dirty white to umber with a white bloom, becoming rust spotted with age. Stem 50–100 x 1–2mm, white at apex, reddish-brown towards the finely hairy base, entirely covered in a fine white velvet. Flesh white in cap, brownish in stem. Gills white to pale yellowish becoming rust spotted. Cheilocystidia and pleurocystidia thin-walled, fusiform. Spore print white. Spores almond-shaped, 8–11 x 6–7um. Cuticular cells smooth and subglobose. Habitat on rhizomes and dead stems of bracken. Season autumn. Occasional. Not edible. Found In Europe.