Three new species of Annulatascus (Ascomycetes) from Hong Kong freshwater habitats

Annulatascus joannae, A. lactus, and A. tropicalis are described and illustrated from decaying woody substrata in freshwater habitats in Hong Kong. Annulatascus joannae is distinguished by ellipsoidal and thick-walled ascospores whereas A. lacteus has milky ascomata and A. tropicalis has relatively large, fusiform, 1–3-septate ascospores. Annulatascus biatriisporus is reported as a new record in Hong Kong. A key to and a synoptic table of Annulatascus species are provided.