쐐기풀과 Urticaceae

1. 가시털이 없다

2. 암술머리는 솔처럼 생기지 않고 암꽃 화피는 통으로 되거나 없다.

3. 잎은 호생한다.

4. 톱니가 없으며 암꽃화피는 막질이다····························································································171. 개물통이

4. 톱니가 있으며 암꽃화피는 육질이다   ························································································ 172. 비양나무

3. 잎은 대생한다  ··························································································································거북꼬리속

2. 암술머리는 솔같고 암꽃화피는 대개 3 개로 깊게 갈라진다.

5. 잎은 대생하며 암꽃화피는 3~5 개로 갈라진다     ····················································································물통이속

5. 잎은 호생한다.

6. 잎 좌우가 비슷하게 생겼다 ·································································································· 159. 나도물통이

6. 잎 좌우가 다르다.

7. 암꽃 화피는 없거나 극히 작고 자화서의 포는 서로 붙어있다  ··························································· 우산물통이속

7. 암꽃 화피는 4-5 개로 갈라지고 자화서의 포는 서로 떨어져 있다  ···················································162. 펠리온나무

1. 가시털이 있다.

8. 수과는 찌그러지고 턱잎은 다소 합생하며 암술머리는 솔모양이 아니다.

9. 암꽃 화피중에서 3 개는 붙었고 1 개는 선형이거나 없다······································································ 148. 큰쐐기풀

9. 암꽃 화피는 약간 붙은 4 개의 화피로 되어있다     ·············································································152. 흑쐐기풀

8. 수과는 곧으며 턱잎은 이생 또는 합생하고 암술머리는 솔같이 생겼다 ································································쐐기풀속