THE GENUS ALEURODISCUS (SENSU LATO) IN NORTH AMERICA

Abstract

The genus Aleurodiscus Rabenh. ex J. Schroet. (sensu lato) is an artificial assemblage of large-spored 'thelephoraceous' hymenomycetes, which can no longer be maintained as a generic unit. The generic limits and the taxonomic position of Aleurodiscus (sensu stricto) (TYPE SPECIES: A. amorphus (Pers. per Purt.: Fr.) J. Schroet.) have been discussed by the writer (1964) in a separate paper. The present work supplements this earlier work, but is concerned primarily with an appraisal of the non-amyloid-spored Aleurodisci, all of which are removed from Aleurodiscus and either assigned to other recognized genera or relegated to new genera.Accordingly, two new genera and 15 new combinations are devised here to accommodate several species formerly placed in Aleurodiscus (sensu lato). The new genera, one of which is monotypical, are Aleurocorticium Lemke, gen. nov. (TYPE SPECIES: A. acerinum (Pers. per Fr.) Lemke, gen. & comb. nov.) and Licrostroma Lemke, gen. nov. (MONOTYPE: L. subgiganteum (Berk.) Lemke, gen. & comb. nov.). The additional 13 combinations proposed are Aleurocorticium album (Viégas) Lemke, comb, nov., A. alliaceum (Quél.) Lemke, comb. nov., A. candidum (Schw.) Lemke, comb. nov. A. dryinum (Pers.) Lemke, comb. nov., A. griseo-canum (Bres.) Lemke, comb. nov., A. lepra (Berk. et Curt.) Lemke, comb. nov., A. macrodens (Coker) Lemke, comb. nov., A. macrosporum (Bres.) Lemke, comb. nov., A. moquiniarum (Viégas) Lemke, comb. nov., A. nivosum (Berk. et Curt. ex Höhn. et Litsch.) Lemke, comb. nov., A. seriatum (Berk. et Curt.) Lemke, comb. nov., A. strumosum (Fr.) Lemke, comb. nov.; and Aleurocystis magnispora (Burt) Lemke, comb. nov.The genus Laeticorticium Donk (1956: 16) (TYPE SPECIES: L. roseum (Pers. per Fr.) Donk) is confirmed as a valid segregate from Aleurodiscus (sensu lato), but the species of Laeticorticium are not treated here aside from nomenclatural considerations. With the exception of the Laeticorticia, all of the remaining North American and many of the critical non-amyloid-spored species of Aleurodiscus (sensu lato) are reviewed.Particular emphasis is devoted to the genus Aleurocorticium Lemke, gen. nov. and a key to 14 North American species of Aleurocorticium is provided. Seven of the Aleurocorticia are reported from the North American mycobiota for the first time. These seven species, five of which are described as new to science, include Aleurocorticium alliaceum (Quél.) Lemke [= Aleurodiscus alliaceus (Quél) Boidin (1957)], Aleurocorticium dryinum (Pers.) Lemke [= Aleurodiscus dryinus (Pers.) Bourd,], Aleurocorticium incrustans Lemke, sp. nov., A. maculatum Jacks. et Lemke, sp. nov., A. mexicanum Lemke, sp. nov., A. microsporum Jacks. et Lemke, sp. nov., and A. pachysterigmatum Jacks. et Lemke, sp. nov.Corlicium hiemale [= Aleurodiscus hiemalis (Laurila) Eriksson (1958a: 78)] is, likewise, initially recorded for North America.Eight of the named species of Aleurodiscus are recognized as facultative synonyms. These names, as indicated, are offered as taxonomic discards: [Aleurodiscus albidus Massee =] Aleurocorticium lepra (Berk. et Curt.) Lemke; [Aleurodiscus albus (Burt) Rogers et Jacks. =] Xenasma clematidis (Bourd. et Galz.) Liberta; [Aleurodiscus guttulatus Rick =] Bourdotia cinerea (Bres.) Bourd. etGalz.; [Aleurodiscus jacksonii Ahmad =] Aleurocorticium candidum (Schw.) Lemke; [Aleurodiscus orientalis Lloyd =] Licrostroma subgiganteum (Berk.) Lemke; [Aleurodiscus reflexus Yasuda =] Licrostroma subgiganteum (Berk.) Lemke; [Aleurodiscus sendaiensis Yasuda =] Corticium evolvens (Fr. ex Fr.) Fr.; [Aleurodiscus subacerinus Höhn. et Litsch. =] Aleurocorticium alliaceum (Quél.) Lemke.The genus Cyphella Fr. (MONOTYPE: C. digitalis (Alb. et Schw. per Pers.) Fr.) is reinstated (see Code 1952: 76) and the combination Aleurodiscus digitalis (Alb. et Schw. per Pers.) Donk (1951: 210) is discredited.