Native to:
Afghanistan,
Alabama,
Alaska,
Albania,
Aleutian Is.,
Arizona,
Arkansas,
Baleares,
British Columbia,
California,
China North-Central,
China South-Central,
China Southeast,
Colorado,
Connecticut,
Denmark,
France,
Føroyar,
Georgia,
Great Britain,
Greece,
Greenland,
Iceland,
Idaho,
Indiana,
Ireland,
Italy,
Japan,
Kamchatka,
Kazakhstan,
Kentucky,
Khabarovsk,
Kirgizstan,
Korea,
Kuril Is.,
Labrador,
Magadan,
Maine,
Maryland,
Massachusetts,
Mexico Northeast,
Mexico Northwest,
Mississippi,
Missouri,
Mongolia,
Montana,
Nevada,
New Brunswick,
New Hampshire,
New Jersey,
New Mexico,
New York,
Newfoundland,
North Carolina,
North European Russi,
Norway,
Nova Scotia,
Nunavut,
Ohio,
Ontario,
Oregon,
Pakistan,
Pennsylvania,
Primorye,
Prince Edward I.,
Qinghai,
Québec,
Rhode I.,
Sakhalin,
South Carolina,
Spain,
Sweden,
Switzerland,
Tadzhikistan,
Tennessee,
Tibet,
Utah,
Uzbekistan,
Virginia,
Washington,
West Himalaya,
West Virginia,
Wyoming,
Xinjiang,
Yugoslavia
Introduced into:
Finland