Heterogastridiales: A New Order of Basidiomycetes

Descriptions are provided of new basidiomycetous taxa based upon the teleomorph of Hyalopycnis blepharistoma; the taxa are: Heterogastridiales, Heterogastridiaceae, Heterogastridium, and Heterogastridium pycnidioideum. The type species is characterized by a pycnidioid basidiocarp with an internal basal hymenium. Phragmobasidia produce sessile, digitately branched basidiospores that are released passively. Ontogeny of the basidia, basidiospores, and septal pores has been studied. The septal pores are simple, but vary morphologically during ontogeny. Hyphal cells, conidiogenous cells, and conidia are dikaryotic. The structure of the spindle pole body indicates heterobasidiomycetous affinities.