Siberian hydrangea

Hime-hydrangea (scientific name: Hydrangea serrata var. yesoensis forma cuspidata) is a native of Japan and a ball-shaped variety of Ezo hydrangea.
Dr. Tomitaro Makino found this flower in the garden of a private house in the Shinetsu region in the early Showa period (1926-1989). He liked this flower with beautiful clear blue petals in a ball shape. It has several thin branches and blooms as if the flowers are piled on top of each other.

Based on the scientific name, the following relationships exist.
Yama-hydrangea (scientific name: Hydrangea serrata)
↓
Ezo hydrangea (scientific name: Hydrangea serrata var. megacarpa), a variety of mountain hydrangea
↓
Hime-hydrangea (scientific name: Hydrangea serrata var. yesoensis forma cuspidata), a horticultural variety of mountain hydrangea

Common name: Hime-hydrangea, scientific name: Hydrangea serrata var. yesoensis forma cuspidata, aka: Makino hime-hydrangea, Regions: Snow covered areas, Height: 100-150 cm, Leaf: thin and glossy, Leaf shape: elliptic, Leaf blade: 6-10 cm, Stipules: opposite, Petiole: present, Leaf margin: sharply serrated, Flower structure: ornamental flower only, Flower color: sky blue, Flowering style: single-petaled, with a small flower bud Flowering season: May - August; inflorescence diameter: 10-15 cm; decorative flower diameter: 3 cm.