사과나무속 Malus MILL.

1. 잎은 겨울눈 중에서 말려있고 성엽은 갈라지지 않는다.

2. 열매에 꽃받침잎이 남는다.

3. 꽃받침잎은 통부보다 길다.

4. 꽃받침의 밑부분에 혹 같은 돌기가 있다 ························································································ 833. 능금

4. 꽃받침의 밑부분에 혹 같은 돌기가 없다 ························································································ 834. 사과

3. 꽃받침잎은 꽃받침통과 길이가 비슷하다 ··················································································· 835. 제주아그배

2. 열매에 꽃받침잎이 없고 암술대는 4~5 개 이다.

5. 꽃받침잎은 통부보다 깊고 좁은 피침형이다 ················································································· 836. 야광나무

5. 꽃받침잎은 통부보다 짧거나 같고 3각상 난형이다 ·············································································· 수사해당화

1. 잎은 겨울눈 중에서 겹쳐있고 적어도 도장지의 잎은 갈라진다.

6. 잎은 갈라지지 않고 예저이다 ········································································································· 서부해당화

6. 도장지의 잎은 갈라진다 ·········································································································· 837. 아그배나무