In between Azolla and Platycarya which one is native to eastern Asia in China, Korea, and Japan?
Azolla Azolla (mosquito fern, duckweed fern, fairy moss, water fern) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, looking nothing like other typical ferns but more resembling duckweed or some mosses.
Azolla cristata Azolla cristata , the Carolina mosquitofern, Carolina azolla, or water velvet, is a species of "Azolla" native to the Americas, in eastern North America from southern Ontario southward, and from the east coast west to Wisconsin and Texas, and in the Caribbean, and in Central and South America from southeastern Mexico (Chiapas) south to northern Argentina and Uruguay.