Question: In between Azolla and Platycarya which one is native to eastern Asia in China, Korea, and Japan?

Related documents: [0]  [DOC] 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. [END] 
[1]  [DOC] Platycarya is a genus of flowering plants in the family Juglandaceae, usually treated as comprising a single species Platycarya strobilacea, though one to two additional species are accepted by some authors. It is native to eastern Asia in China, Korea, and Japan. [END]  
Answer: Platycarya
Platycarya