Spores narrowly ellipsoid to allantoid, hyaline, smooth. Virions are bacilliform, ovoid, and allantoid. The spores are ellipsoid or sausage-shaped (allantoid), smooth, and thin-walled. Specifically, "P. curvatum" is characterized by its grayish white colonies and its allantoid conidia. These spores are allantoid (sausage-shaped) or less commonly oblong to cylindrical.