| Family | Asteraceae (alt. Compositae) |
| Scientific name | Crepidiastrum platyphyllum (Franchet & Savatier) Kitamura |
| Synonyms | Crepis integra Miquel var. platyphylla Franchet & Savatier; Crepis lanceolata (Houttuyn) Schultz-Bipontinus var. plathyphylla (Franchet & Savatier) Makino; Crepidiastrum lanceolatum (Houttuyn) Nakai var. platyphyllum (Franchet & Savatier) Nakai; Ixeris lanceolata (Houttuyn) Stebbins subsp. platyphylla Stebbins; Lactuca platyphylla (Franchet & Savatier) Makino |
| Common name | (Japanese common name) wadan (ワダン [meaning of wadan is unknown]) |
| (English common name) none | |
| Distribution | (Japan) Honshu (Chiba Prefecture, Kanagawa Prefecture, Shizuoka Prefecture, Izu Islands) |
| (Other nations) none | |
| Habitat | Seaside rocks |
| Chromosomal number | 2n=10 |
| Description | Plants ca. 10-30cm tall. Leaves 8-15cm long. Flowers yellow ca. 5mm across, flowering in July to November. Perennial plants. |
| Reference | Crepidiastrum platyphyllum Tuyama |
| Phylogenetic and Biogeographic Study of Crepidiastrum platyphyllum (Compositae) in the Coastal Area of the Sagami Sea, Japan | |
| A chromosomal comparison of three species of Crepidiastrum, section Suffruticosae(Asteraceae) by fluorescent in situ hybridization using ribosomal DNA probe | |
| Plant germination inhibitor and method of use thereof (European Patent Application EP1736053/2006) | |
| Health food and method for producing the same (Japanese Patent JP2007151431) | |
| Note | Native to Japan. |
| November 2009 at Tsukuba Botanical Garden |
November 2009 at Tsukuba Botanical Garden |