사시나무속 PopuluS LINN.

1. 잎에 털이 없다.

2. 잎 가장자리에 투명선이 없다.

3. 잎자루는 좌우로 편평하다.

4. 짧은 가지에 달린 잎새 밑에는 보통 선점이 없다  ············································································ 8. 사시나무

4. 잎새 밑 선점은 확실하고 어린가지와 겨울 눈에는 털이 약간 있다  ·················································· 9. 일본사시나무

3. 잎자루는 둥글다

5. 새가지는 황회색 내지 주황색이다.

6. 어린 가지는 털이 없거나 다소 털이 았으며 점질이 없다. 옆자루는 김이 1-4 cm이다.

7. 잎에 털이 없고 난형 또는 좁은 난형예두이다··············································································· 중국황철

7. 잎은 뒷면 맥 상에 털이 있고 갑자기 좁아진다   ········································································11. 황철나무

6. 어린 가지는 점질이 있고 잎자루는 길이 1 ~3.5cm 이다  ·····························································12. 물황철나무

5. 가지는 갈색이며 털이 없다. 잎은 중앙보다 위쪽이 넓고 잎자루는 길이 0.5-2.5 cm 이다  ································13. 당버들

2. 잎 가장자리에 투명선이 있다.

8. 잎새 밑에 선점이 없고 높이가 너비보다 짧다 ·····················································································14. 양버들

8. 잎새 밑에 선점이 있고 높이가 너비보다 길다.

9. 잎은 어릴 때 녹색이며 맹아의 가지에 능선이 있다  ·········································································15. 미루나무

9. 잎은 어릴 때 붉은빛이 돈다  ·······························································································17. 이태리포플러

1. 잎에 털이 있다.

10. 잎에 흰 털이 발생하고 가장자리가 갈라진다  ·······················································································10. 은백양

10. 잎에 흰 털이 많고 갈라지지 않는다 ·····························································································16. 은사시나무