calamus
americanus
Canada, northern United States, Buryatiya region of Russia
angustatus
Siberia, China, Russian Far East, Japan, Korea, Mongolia, Himalayas, Indian Subcontinent, Indochina, Philippines, Indonesia
calamus
Siberia, Russian Far east, Mongolia, Manchuria, Korea, Himalayas; naturalized in Europe, North America, Java and New Guinea
gramineus