Cap 35-120 mm broad, hemispheric to convex becoming plano-convex, not striate, dry, glabrous, sometimes wrinkled or crackled at the center, cream to pale brownish cream. Flesh thick; odor buttery. Gills adnate, close, broad, pale grayish brown to brown. Stem 50-140 x 5-15 mm, cylindrical or enlarged below, solid, tough, fibrillose-striate, white to dingy tan; with a persistent, membranous, pendulous, white annulus near the apex. Spore Deposit brown. Edibility: edible and choice.
Agrocybe parasitica, a species common to Australasia, is closely related to the north temperate A. cylindrica, differing only at the microscopic level. The Hawaiian species appears on standing and fallen manele (Sapindus saponaria) trees in Kipuka Puaulu (Bird Park) and Kipuka Ki within the Volcanoes National Park. The fruiting bodies form large caps up to 4 to 5 inches in diameter and have a large drooping annulus on the stem. Like its cousin A. cylindrica, A. parasitica is an excellent edible species, and it is easily cultivated on hardwood chips. In Europe, A. cylindrica, known there as A. aegerita or the Black Poplar Mushroom, is commercially cultivated. Is: HA.