noun
threeleaf arrowhead (Sagittaria trifolia)
A perennial aquatic plant with arrow-shaped leaves, native to East Asia. The corms are edible and known as クワイ.
田んぼの隅にオモダカが生えている。
Threeleaf arrowhead is growing in the corner of the rice paddy.
オモダカの葉は矢じりのような形をしている。
The leaves of the threeleaf arrowhead are shaped like arrowheads.
クワイ refers specifically to the edible corm of the threeleaf arrowhead (Sagittaria trifolia var. edulis), often eaten in Japanese cuisine, while オモダカ is the general name for the plant.
The name オモダカ is thought to derive from the shape of the leaves resembling a raised face (面高), but the exact origin is uncertain.