거머리말과 Zosteraceae

1. 꽃은 1 가화이고 열매는 난형이며 잎은 가장자리가 밋밋하다 ········································································ 거머리말속

1. 꽃은 2 가화이고, 열매는 심장저이며 잎에 톱니가 있다 ·················································································26. 새우말

거머리말속 Zostera LINN.

1. 잎은 너비 3-15mm이고 포의 잎집은 닫혀 있으며 꽃차례에 포 같은 열편이 없다.

2. 잎은 너비 3-7mm이다.

3. 줄기에 포복지가 있고 잎은 너비 3-5mm 이다  ··················································································23. 거머리말

3. 줄기는 포복지가 없고 총생하며 잎은 너비 7mm이다 ····································································23+. 포기거머리말

2. 잎은 너비 10-15mm이다.

4. 긴 가지 끝에 잎이 많이 달리고 밑에는 꽃차례가 달린다. 잎은 원두이고 열매에는 세로줄이 있다 ·················· 24+. 수거머리말

4. 긴 가지에는 끝까지 꽃차례가 붙는다. 잎은 끝이 파지고 열매에 줄이 없다················································ 24. 왕거머리말

1. 잎은 너비 1.5~2mm 이고 포의 잎집은 열려있으며 꽃차례에 포 같은 열편이 있다  ········································ 25. 애기거머리말