noun
heartshape false pickerelweed
A species of aquatic plant (Monochoria vaginalis) found in paddy fields and wetlands. The name is usually written in kana.
田んぼにコナギがたくさん生えている。
A lot of heartshape false pickerelweed is growing in the rice paddy.
The name likely derives from 小 (ko, 'small') + 菜葱 (nagi, a type of water plant), but the exact origin is uncertain.