horse chestnut; conker tree
Refers to the tree Aesculus hippocastanum, known for its conkers. Botanical term.
A large horse chestnut tree is planted in the park.
The fruit of the horse chestnut is also called marronnier.
Refers to the Japanese horse chestnut (Aesculus turbinata), a related native species.
Katakana spelling is standard for this plant name.
Kanji spelling is rare; the word is usually written in kana.
Compound of 西洋 (せいよう, 'Western') + 栃の木 (とちのき, 'horse chestnut tree').