The Pseudoomphalina kalchbrenneri complex in North America

Pseudoomphalina kalchbrenneri is a Eurasian species. In North America the Pso. kalchbrenneri complex is represented by Pseudoomphalina anticostica sp. nov. and Pso. compressipes in the east and Pso. intermedia in the west. Pseudoomphalina farinacea and Pso. felleoides are later synonyms for Pso. compressipes. The somewhat similar Pseudolaccaria pachyphylla occupies a temperate band through Eurasia, confirmed by sequencing in both eastern and western North America. It differs from species of the Pso. kalchbrenneri complex by smaller size, finely granular pileus, non-decurrent gills, and lack of hymenial cystidia. All species of the Pso. kalchbrenneri complex are uncommon, and macroscopically similar. Pseudoomphalina kalchbrenneri and Pso. intermedia can be identified by their distribution (Europe and western North America, respectively) and lack of cystidia. The cystidiate eastern North American Pso. anticostica and Pso. compressipes can be differentiated by the smaller spores of the latter. Pseudoomphalina cokeri is the most ancestral species on the Pseudoomphalina lineage, while Clitocybe thujana and Agaricus apertus (Clitocybe/Clitocybula aperta) fall outside Pseudoomphalina and Pseudolaccaria. We add 21 new sequences to GenBank, including six types (Agaricus compressipes, Clitocybe felleoides, C. farinacea, C. intermedia, C. thujana, Agaricus apertus), and one new species (Pso. anticostica). Key words: ITS sequences, holotype barcoding, molecular phylogeny, Tricholoma. Resume : Pseudoomphalina kalchbrenneri est une espece eurasienne. En Amerique du Nord, le complexe Pso. kalchbrenneri est represente par Pseudoomphalina anticostica sp. nov. et Pso. compressipes dans l'est et Pso. intermedia dans l'ouest. Pseudoomphalina farinacea et Pso. felleoides sont des synonymes posterieurs de Pso. compressipes. Pseudolaccaria pachyphylla, assez similaire, occupe une bande temperee a travers l'Eurasie, ce que confirme le sequencage realise dans l'est et l'ouest de l'Amerique du Nord. Il differe des especes du complexe Pso. kalchbrenneri par sa taille plus petite, un chapeau finement granuleux, des lames non decurrentes et l'absence de cystides dans l'hymenium. Toutes les especes du complexe Pso. kalchbrenneri sont rares et similaires a l'echelle macroscopique. Pseudoomphalina kalchbrenneri et Pso. intermedia peuvent etre identifies par leur distribution (Europe et ouest de l'Amerique du Nord, respectivement) et l'absence de cystides. Pseudoomphalina anticostica et Pso. compressipes, especes cystidiees de l'est de l'Amerique du Nord, peuvent etre differencies par les spores plus petites du dernier. Pseudoomphalina cokeri est l'espece la plus ancestrale de la lignee des Pseudoomphalina, alors que Clitocybe thujana et Agaricus apertus (Clitocybe/Clitocybula aperta) se situent a l'exterieur des Pseudoomphalina et Pseudolaccaria. Les auteurs ajoutent 21 nouvelles sequences a GenBank, dont six types (Agaricus compressipes, Clitocybe felleoides, C. farinacea, C. intermedia, C. thujana, Agaricus apertus) et une nouvelle espece (Pso. anticostica). [Traduit par la Redaction] Mots-cles : sequences de l'ITS, codage a barre d'holotypes, phylogenie moleculaire, Tricholoma.
Introduction Traditionally, the genus Tricholoma Fr. was the repository for a wide variety of fungi that could not be placed elsewhere, which eventually necessitated dissection of diverse unrelated groups. Singer [...]