Two New Species of Hygroaster from Madagascar

The genus Hygroaster (Hygrophoraceae, Hygrophorineae) is a small genus with a tropical distribution. Based on morphological and phylogenetic analysis, two new species, H. madagascarensis and H. andasibensis , are described from Madagascar. They are the first species of this genus described from Africa. To stabilize the nomenclature, the type specimens of H. nodulisporus , the type species of the genus, and H. fucatus were studied. The initial combination of the name Hygrophorus nodulisporus in the genus Hygroaster was invalid and is thus validated here. In addition, our study revealed that H. fucatus belongs to the genus Asproinocybe in suborder Tricholomatineae, whose representatives also have nodulose basidiospores. A new combination A. fucata is proposed.