Pseudonectria rousseliana (Mont.) Seaver is fully described and the presence of a hypostroma connecting this fungus to the host is reported. Volutella buxi (Cda.) Berk, is proved to be the imperfect stage of Pseudonectria. Verticillium buxi (Link) Auersw. is not a conidial stage of Pseudonectria. It is renamed Paecilomyces buxi (Link ex Fr.) comb. nov.