Hypsizygus tessulatus (Bull. ex Fr.) Singer Cap 5-15cm across, convex becoming flatter and rather sunken; white to buff yellow, creamy tan or crust brown in the center; moist, smooth, minutely hairy, becoming cracked with scaly patches. Gills adnexed to sinuate, close to subdistant, broad; whitish becoming cream. Stem 40-110 x 10-30mm solid, off-center, enlarged toward the base; white; dry, smooth, sometimes hairy. Flesh thick, firm; white. Odor mushroomy. Taste mild. Spores globose, smooth, 5-7 x 5-7µ. Deposit white to buff. Habitat singly or scattered on old hardwood trees, especially elm, often quite high up. Frequent. Found Europe and northern North America. Season September-December. Edible but tough. Comment Formerly known as Pleurotus ulmarius, sensu American authors.