| Family | Rosaceae |
| Subfamily | Rosoideae |
| Tribe | Colurieae |
| Scientific name | Geum japonicum Thunberg |
| Synonyms | Geum iyoanum Koidzumi; Geum japonicum Thunberg forma iyoanum (Koidzumi) H. Ikeda; Geum japonicum Thunberg var. iyoanum Murata |
| Common name | (Japanese common name) daikon-sou (ダイコンソウ, 大根草 [meaning: white radish weed]) |
| (English common name) Japanese avens | |
| Distribution | (Japan) Hokkaido, Honshu, Shikoku, Kyushu |
| (Other nations) Korea | |
| Habitat | Mountane forest edge. |
| Chromosomal number | 2n=42 |
| Description | Plants 40-70cm tall. Leaves 10-20cm long. Flowers yellow 15-20mm across, flowering in June to August. Perennial plants. |
| Reference | Geum japonicum Thunb. |
| Geum japonicum Thunberg var. chinense F. Bolle |
| July 2007 at mountane roadside |
July 2007 at mountane roadside |
July 2007 at mountane roadside |
| April 2009 at my home |
April 2009 at my home |