Asia-Temperate: Taiwan (Taiwan present), Asia-Tropical: Borneo present; Jawa (Jawa present); Lesser Sunda Is. present; Malaya (Peninsular Malaysia present); Maluku (Maluku present); New Guinea present; Philippines (Philippines present); Sumatera (Sumatera present), Halmahera present, Himalayas to Indochina present, Japan present
Himalayas to Indochina, China, Japan, Taiwan. In Malesia: Sumatra, Peninsular Malaysia, Java, Lesser Sunda Islands, Borneo, Philippines, Moluccas (Halmahera), New Guinea.
A species with narrow, rheophytic, and wider land forms sometimes growing close together. Most easily recognisable by the row of large areoles, but the narrow rheophytic fronds can be recognised best by the rather dense cover of scales on the costa. A row of smaller areoles is often distinguishable within the main areole. Sometimes the sori are situated more or less in one row between the veins. Occasionally, especially in submerged plants, the apex of the lamina is proliferous.