Stereum radicans, clavariadelphus and the gomphaceae

The nomenclatorial travels of Stereum radicans from genus to genus represent attempts by hard-pressed mycologists to settle this species into a taxonomically more comfortable situation. Originally described as a Thelephora, Patouillard removed it to his Podoscypha, where he accommodated most of the "stipitate Stereums." Burt transferred the species to Stereum but later (Ann. Missouri Bot. Gard. 13: 326. 1926), discovering that the spores darken with age, returned it to Thelephora. Since these reports, additional information has accumulated which indicates a more realistic disposition of S. radicans. Martin (Lloydia 7: 77. 1944 Welden (Bull. Torrey Club 81: 432. 1954), and Boidin (Bull. Jard. Bot. Bruxelles 30: 291. 1960), basing their work on recently collected material, have microscopically analyzed the species. Neither Martin nor Welden attempted to move the species from Stereum, but Boidin has suggested transferring it to either Cotylidia or Podoscypha. He tends to favor Cotylidia because of the hyphal construction of S. radicans. In 1958 (Lloydia 21: 38-44) I demonstrated that Cotylidia is a homogeneous group of more or less stipitate fungi of relatively simple construction and bibulous texture. The basidiocarps are white to pale yellow in the field and darken only slightly in drying or with age. The laterallv stipitate pilei lack a cuticle and are constructed of thinto thick-walled hyaline, branching hyphae, without clamp-connections, arranged in a parallel manner within the context. Leptocystidia, arising from deep within the context, grow downward and penetrate the hymenium in some species, but these are absent in others. The hymenium is composed of cylindrical-clavate basidioles and basidia, the basidia producinlg hyaline, smooth, thin-walled spores on four slender sterigmata. These spores remain hyaline with age. Podoscypha is composed of species which have a relatively more complex structure. The basidiocarps are laterally stipitate to infundibuliform and have a more or less coriaceous texture, particularly when dry. In the field these sporocarps may be white to deep reddish-brown; the former become reddish-brown in age and in drying; the latter do not change or only become darker. A well-developed cuticle is present, composed of thick-walled hyphae with the pigment localized in the hyphal walls. Thin-walled hyaline, branching hyphae with clamp-connections and thick-walled seldom-branched hyaline hyphae compose the context. The thick-walled hyphae are the skeletals. These skeletal hyphae, especially adhymenially, often produce short branches and twist and turn among the other hyphae. In this, they appear nearly as binding hyphae. The pseudocystidia (gloeoeystidia) arise from generative hyphae within the context and project from the surface of the stalk and pileus and into the hymenium. Those projecting from the stalk and from the abhymenial suriace of the pileus often thicken considerably, become pigmented, and form the pileo-and caulocystidia. Those which project into the hymenium remain thin-walled or thicken only slightly, but remain hyaline. Basidia and basidioles compose the hymenium. The basidia, which may become