포도과 Vitaceae

1. 초본성이며 꽃잎은 4 개이다 ········································································································ 1132. 거지덩굴

1. 목본식물이며 꽃잎은 5개이지만 간흑 4개인것도 있다.

2. 줄기의 골속은 갈색이며 피목이 없고 세로로 갈라지며 꽃은 원추화서에 달린다 ···················································· 포도속

2. 줄기의 골속은 희고 피목이 있으며 벗져지지 않고 꽃은 취산화서에 달린다.

3. 술잔처럼 생긴 화반은 씨방을 둘러싸고 덩굴손은 흡반 같지 않다 ······························································· 개머루속

3. 화반은 술잔처럼 생기지 않고 씨방에 붙었으며 덩굴손은 흡반 같이 생겼다 ··············································· 담쟁이덩굴속