Azolla filiculoides Lam. (New World: Alaska, Argentina Northeast, Argentina Northwest, Argentina South, Arizona, Arkansas, Bolivia, Brazil North, Brazil Northeast, Brazil South, Brazil Southeast, Brazil West-Central, British Columbia, California, Chile Central, Chile North, Chile South, Colombia, Colorado, Costa Rica, Dominican Republic, Ecuador, El Salvador, Galápagos, Guatemala, Guyana, Honduras, Illinois, Iowa, Kansas, Mexico Central, Mexico Gulf, Mexico Northeast, Mexico Northwest, Mexico Southeast, Mexico Southwest, Minnesota, Missouri, Nebraska, Nevada, New Mexico, Nicaragua, Oklahoma, Oregon, Panamá, Paraguay, Peru, Texas, Tristan da Cunha, Uruguay, Utah, Venezuela, Venezuelan Antilles, Washington, Wisconsin; Introduced into: Albania, Assam, Austria, Baltic States, Bangladesh, Belgium, Bulgaria, Canary Is., Cape Provinces, China Southeast, Czechoslovakia, Denmark, France, Free State, Germany, Great Britain, Greece, Hawaii, Hungary, India, Ireland, Italy, Japan, Jawa, Korea, KwaZulu-Natal, Lesotho, Malaya, Morocco, Mozambique, Namibia, Nansei-shoto, Nepal, Netherlands, New York, Northern Provinces, Pakistan, Palestine, Poland, Portugal, Romania, Sardegna, Sicilia, Spain, Swaziland, Sweden, Tadzhikistan, Taiwan, Turkey, Turkey-in-Europe, West Himalaya, Yugoslavia, Zimbabwe as per POWO)
Azolla pinnata subsp. asiatica R.M.K.Saunders & K.Fowler (China to Tropical & Subtropical Asia: Assam, Bangladesh, Borneo, China North-Central, China South-Central, China Southeast, East Himalaya, India, Japan, Jawa, Korea, Lesser Sunda Is., Malaya, Maluku, Manchuria, Myanmar, Nansei-shoto, Nepal, New Guinea, Pakistan, Philippines, Sri Lanka, Sulawesi, Sumatera, Taiwan, Thailand, Vietnam, West Himalaya as per POWO)
