Agaricales of the Hawaiian Islands. 6. Agaricaceae I. Agariceae: Agaricus and Melanophyllum

Nineteen species belonging to Tribe Agariceae (Agaricaceae) are reported fr om the Hawaiian Islands. This group, the dark spored members of the Agarica ceae, is represented in the Hawaiian Islands by eighteen species of Agaricu s and one species of Melanophyllum. Of these species, all are found only in alien habitats, nine are new, and sixteen are first reports. All taxa are described, illustrated, and compared with phenetically similar taxa, and an artificial dichotomous key to aid in determining Hawaiian Agaricus and Mel anophyllum species is presented.