Distribution
Asia-Tropical: Philippines (Philippines present), Batanes Islands present
Malesia: Philippines (Batanes Islands, 3 collections).
Notes
This very interesting and isolated species needs further study. The type of C. irayensis resembles species of Plesioneuron in aspect and texture, but its glands (on sporangia), and venation and sinus-characters are unlike that genus.
Citation
Copel. 1960: Fern Fl. Philip.: 340