Eleocharis kuroguwai; a species of spikerush
A specific aquatic plant native to Japan; the name is often used in botanical or agricultural contexts.
Kuroguwai is a perennial plant found in paddy fields.
Chinese water chestnut; Eleocharis dulcis var. tuberosa
Refers to the edible corm of a related species; often distinguished from the native Japanese species by the cross-reference to 大黒慈姑.
See also: オオクログワイ
The corms of the Chinese water chestnut are used in Chinese cuisine.
Chinese water chestnut
Katakana spelling is standard for this plant name; usually written in kana.
Kanji spelling is rare and mainly found in botanical contexts.
The name クログワイ literally means 'black arrowhead' (黒慈姑), likely from the dark color of the plant's tubers. The exact origin is uncertain.