Genus Azetouna - Ridge and ridge

...The Japanese name is said to be a derivative of Watana, which means a vegetable that grows in the sea (wata). The genus Crepidiastrum , to which this species belongs, is endemic to East Asia and has about 10 species, with two other species distributed in Japan, including C. keiskeanum Nakai. C. keiskeanum grows on sea cliffs from Izu to Kyushu, and its basal leaves are spatula-shaped and smaller than those of C. keiskeanum.

*Some of the terminology explanations that mention the genus "Azetuna" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…和名は，海(ワタ)に生える菜を意味するワタナの転じたものといわれる。　本種の属するアゼトウナ属Crepidiastrumは，東アジアの固有属で，約10種あり，日本には他にアゼトウナC.keiskeanum Nakaiなど2種が分布する。アゼトウナは伊豆～九州の海崖に生育し，根生葉はへら形で，ワダンより小さい。…

※「アゼトウナ属」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報