Cardiandra alternifolia (species of hydrangea)
A species of hydrangea native to Japan; the name is usually written in katakana as クサアジサイ.
Cardiandra alternifolia grows wild in moist mountainous areas.
アジサイ is the common hydrangea, while クサアジサイ is a specific species with smaller, more delicate flowers.
Katakana spelling is common for plant names; usually written in kana.
Kanji spelling is rare; the plant is usually written in kana.
From 草 (kusa, 'grass') + 紫陽花 (ajisai, 'hydrangea'), referring to its herbaceous nature compared to woody hydrangeas.