연리초속 Lathyrus LINN.

1. 덩굴손이 있다.

2. 줄기에 날개가 없다

3. 꽃차례에 꽃이 많다 ················································································································ 926. 활량나물

3. 꽃차례에 꽃이 적다 ·················································································································· 927. 갯완두

2. 줄기에 날개가 있다.

4. 소엽은 1~3 쌍이다.

5. 덩굴손은 갈라지지 않는다 ········································································································ 928. 연리초

5. 덩굴손은 갈라진다 ···············································································································929. 털연리초

4. 소엽은 1 쌍이다 ···················································································································· 932. 스위트피

1. 덩골손이 없다.

6. 줄기에 날개가 있다 ·················································································································· 930. 선연리초

6. 줄기에 날개가 없다 ····················································································································· 931. 산새콩