A new species of Hypocrella, H. macrostroma, and its phylogenetic relationships to other species with large stromata.

Two specimens of a new species of Hypocrella with large stromata were collected in Bolivia and Costa Rica. The morphology of the new species, H. macrostroma sp. nov., was compared with that of other species with large stromata, i.e. H. africana, H. gaertneriana, and H. schizostachyi. In addition, phylogenetic analyses of partial sequences from three genes, large subunit nuclear ribosomal DNA (LSU), translation elongation factor 1-alpha (EF1-alpha), and RNA polymerase II subunit 1 (RPB1), were conducted to determine the relationships of the new species to other species of Hypocrella/Aschersonia. Phylogenetic analyses show that H. macrostroma belongs to a strongly supported clade that includes H. africana, H. schizostachyi, and Aschersonia insperata, whereas other Hypocrella species belong to two sister clades. Hypocrella macrostroma is described and illustrated, and a lectotype is designated for H. gaertneriana.