개암나무속 Corylus LINN.

1. 총포는 2 개의 포영으로 되었으며 밖에서 종자가 보인다.

2. 총포 열편은 밋밋하거나 톱니가 있다 ································································································· 양개암나무

2. 총포 열편은 톱니가 있다.

3. 잎은 절두로서 주맥의 끝이 특히 길다 ···················································································80. 난티잎개암나무

3. 잎은 예두이며 결각상 톱니가 있다 ····························································································· 81. 개암나무

1. 총포는 통형이며 열매가 안에 들어있다.

4. 총포는 열매 전체를 둘러싸지만 끝이 길게 자라지 않는다 ····································································82. 병개암나무

4. 총포는 끝이 길게 자란다.

5. 총포는 끝이 좁아지고 잎은 결각이 뚜렷하지 않다 ··········································································83. 참개암나무

5. 총포는 통부는 아래 위의 지름이 비슷하고 잎은 결각이 뚜렷하다 ························································ 84. 물개암나무