meadowsweet (Filipendula multijuga)
A flowering plant native to Japan, often found in mountainous areas. The name is also used for other Filipendula species.
In summer, you can see meadowsweet blooming in the mountains.
Mixed kanji-kana spelling; commonly used for this plant.
Full kanji spelling; less common and may be unfamiliar to some readers.
Katakana spelling often used in botanical contexts; usually written in kana.
The name しもつけそう is said to derive from 下野 (Shimotsuke, an old province corresponding to modern Tochigi Prefecture) where the plant was first discovered, combined with 草 (grass/herb).