A new Neopaxillus species (Agaricomycetes) from the Dominican Republic and the status of Neopaxillus within the Agaricales

The new species Neopaxillus dominicanus is described on the basis of collections from the Dominican Republic. It is distinguished by having a basidiome with decurrent, distant, white lamellae with evident pink-lilac tinges, the non-depressed pileus at maturity and well developed catenulate cheilocystidia. A description, color photographs of fresh basidiomes and line drawings of relevant microscopic traits are provided. N. dominicanus is morphologically similar to Neopaxillus echinospermus, the type species of the genus. Based on comparative ITS-LSU rDNA gene sequence analyses, Neopaxillus, formerly placed in the Boletales, is considered within the Agaricales where it is sister to Crepidotus (Crepidotaceae), and N. dominicanus is supported as distinct from N. echinospermus. Finally, according to our morphological and molecular analyses, two collections of N. echinospermus from Mexico are referable to N. dominicanus.