오이풀속 Sanguisorba LINN.

1. 꽃차례는 곧고 길이 3-8cm로서 밑에서부터 피기 시작하며 소엽은 5-6쌍이다 ·············································· 778. 큰오이풀

1. 꽃차례는 곧거나 처지고 위에서부터 피기 시작한다.

2. 꽃차례는 처지고 수술은 6-12 개이며 꽃은 홍자색이다 ······································································· 779. 산오이풀

2. 수술은 4개이다.

3. 꽃차례는 길이 1-2.5 cm 이고 꽃은 검은 혈적색이다 ········································································· 776. 오이풀

3. 꽃차례는 길이 2~7cm 이다.

4 소엽은 11-15 개로서 너비 5-20mm 이고 꽃은 희다 ··································································· 777. 가는오이풀

4. 소엽은 5-9 개로서 너비 8-10mm 이고 꽃은 홍자색이다 ································································ 780. 긴오이풀