개구리밥과 Lemnaceae

1. 식물체는 뿌리가 없고 극히 작으며 1 개의 눈이 중앙에 생긴다 ··································································· 분개구리밥

1. 식물체는 편평하고 뿌리가 있다.

2. 뿌리는 여러 개이고 잎 같은 식물체의 뒷면은 보통 자줏빛이 돈다 ·························································475. 개구리밥

2. 뿌리는 1개이고 잎 같은 식물체의 뒷면은 녹색이지만 간혹 자줏빛이 도는 것이 있다 ································· 476. 좀개구리밥