noun
blue spirea; blue mist shrub
A flowering plant (Caryopteris divaricata) known for its blue flowers. The name is usually written in katakana.
庭にカリガネソウが咲いている。
Blue spirea is blooming in the garden.
カリガネソウは秋に青い花をつける。
Blue mist shrub produces blue flowers in autumn.
The name かりがねそう (雁金草) literally means 'wild goose plant', likely from the shape of the flower resembling a flying goose. The exact origin is uncertain.