Phylogenetic origins and family classification of typhuloid fungi, with emphasis on Ceratellopsis, Macrotyphula and Typhula (Basidiomycota)

Typhuloid fungi are a very poorly known group of tiny clavarioid homobasidiomycetes. The phylogenetic position and family classification of the genera targeted here, <i>Ceratellopsis</i>, <i>Macrotyphula</i>, <i>Pterula sensu lato</i> and <i>Typhula</i>, are controversial and based on unresolved phylogenies. Our six-gene phylogeny with an expanded taxon sampling shows that typhuloid fungi evolved at least twice in the <i>Agaricales</i> (<i>Pleurotineae</i>, <i>Clavariineae</i>) and once in the <i>Hymenochaetales</i>. <i>Macrotyphula</i>, <i>Pterulicium</i> and <i>Typhula</i> are nested within the <i>Pleurotineae</i>. The type of <i>Typhula</i> (1818) and <i>Sclerotium</i> (1790), <i>T. phacorrhiza</i> and <i>S. complanatum</i> (synonym <i>T. phacorrhiza</i>), are encompassed in the <i>Macrotyphula</i> clade that is distantly related to a monophyletic group formed by species usually assigned to <i>Typhula</i>. Thus, the correct name for <i>Macrotyphula</i> (1972) and <i>Typhula</i> is <i>Sclerotium</i> and all <i>Typhula</i> species but those in the <i>T. phacorrhiza</i> group need to be transferred to <i>Pistillaria</i> (1821). To avoid undesirable nomenclatural changes, we suggest to conserve <i>Typhula</i> with <i>T. incarnata</i> as type. <i>Clavariaceae</i> is supported as a separate, early diverging lineage within <i>Agaricales</i>, with <i>Hygrophoraceae</i> as a successive sister taxon to the rest of the <i>Agaricales</i>. <i>Ceratellopsis s. auct.</i> is polyphyletic because <i>C. acuminata</i> nests in <i>Clavariaceae</i> and <i>C. sagittiformis</i> in the <i>Hymenochaetales</i>. <i>Ceratellopsis</i> is found to be an earlier name for <i>Pterulicium</i>, because the type, <i>C. queletii</i>, represents <i>Pterulicium gracile</i> (synonym <i>Pterula gracilis</i>), deeply nested in the <i>Pterulicium</i> clade. To avoid re-combining a large number of names in <i>Ceratellopsis</i> we suggest to conserve it with <i>C. acuminata</i> as type. The new genus <i>Bryopistillaria</i> is created to include <i>C. sagittiformis</i>. The families <i>Sarcomyxaceae</i> and <i>Phyllotopsidaceae</i>, and the suborder <i>Clavariineae</i>, are described as new. Six new combinations are proposed and 15 names typified.