| Family | Hydrangeaceae |
| Scientific name | Hydrangea involucrata Siebold |
| Synonyms | none |
| Common name | (Japanese common name) tama-ajisai [balls Hydrangea] |
| (English common name) none | |
| Distribution | (Japan) Honshu (south of Fukushima Prefecture, north of Central region) |
| (Other nations) none | |
| Chromosomal number | 2n=30 |
| Description | Plants 1.5-2m. Leaves 10-20cm. Flowers purple (merely white), flowering in July to September. Deciduous. Shrub. |
| Reference | Hydrangea involucrata Siebold |
| July 2007 at Mt. Tsukuba | July 2007 at Mt. Tsukuba | July 2007 at Mt. Tsukuba |
| July 2007 at Mt. Tsukuba |