나자스말과 Najadaceae

나자스말속 Najas LINN.

1. 잎집에 톱니가 없다. 잎은 너비 2~3mm로서 9~11쌍의 톱니가 있다·························································· 20. 민나자스말

1. 잎집에 톱니가 있다.

2. 잎집은 튀어나오지 않고 수꽃에 포초가 있다 ·················································································21. 톱니나자스말

2. 잎집 끝은 귀처럼 튀어나오고 꽃에 포초가 없다 ··················································································22. 나자스말