여뀌속 Persicaria MILL.

1. 2 개로 갈라진 암술대는 뒤로 젖혀진다 ································································································215. 이삭여뀌

1. 암술대는 2-3 개로 갈라지고 떨어진다.

2. 줄기에 밑을 향한 잔가시가 있다.

3. 턱잎의 끝은 잎같이 생겼다.

4. 잎은 3각형이며 길이와 너비의 길이가 비슷하고 중간이 파지지 않았다.

5. 줄기는 덩굴성이다.

6. 잎자루가 잎새 뒷면에 달렸고 잎은 끝이 뾰족하다·····································································216. 며느리배꼽

6. 잎자루가 잎새 밑에 달렸고 잎은 끝이 뾰족하다 ····································································217. 며느리밑씻개

5. 줄기는 옆으로 자라지만 다른 물체에 기어오르지 않는다 ·································································218. 세뿔여뀌

4. 잎은 난상 3각형이며 길이가 너비보다 길고 중간이 파졌다.

7. 잎집 가장자리에 톱니가 있다. 잎의 열편은 좁고 전체에 성모가 많다 ··········································219. 나도미꾸리낚시

7. 잎집 끝은 대개 밋밋하고 잎의 열편은 넓으며 성모가 적다··································································220. 고마리

3. 턱잎 가장자리는 잎같이 넓어지지 않았다.

8. 잎은 밑이 좁아진다 ···············································································································221. 바늘여뀌

8. 잎은 절저 또는 심정·저이며 흔히 3개로 갈라진다.

9. 잎집은 길이 3~4mm 로서 털이 있고 꽃은 수상화서에 1~3개씩 달린다 ·············································222. 긴화살여뀌

9. 잎집은 길이 7-20mm 로서 털이 없거나 약간 있다.

10. 꽃은 약간 이삭처럼 붙어서 전체가 원추상이 되며 잎집 끝에 털이 없다 ·································223. 좁은잎미꾸리낚시

10 꽃차례는 둥글며 꽃이 밀생한다.

11. 잎집 끝은 비스듬히 잘리고 털이 거의 없다. 잎은 갚은 섬장저이고 소화경은 포보다 짧다 ·················225. 미꾸리낚시

11. 잎집 끝은 수평으로 잘라고 잎의 열편은 벌어졌다.

12. 소화경은 포보다 길다 잎은 밑부분이 화살밑처럼 된다 ·····················································224. 긴미꾸리낚시

12. 소화경은 포보다 짧다. 잎의 열편은 절저로서 끝이 둔하다 ···········································226. 넓은잎미꾸리낚시

2. 밑을 향한 가시가 없다.

13. 꽃차례는 둥글다

14. 옆으로 자라다가 곧추선다. 잎 뒷면에 선점이 있다   ··········································································228. 산여뀌

14. 줄기는 덩쿨성이다. 잎에 선점이 없다 ····················································································· 228+. 민고마리

13. 꽃차례는 원주형 또는 선형이다.

15. 잎집은 통상이며 잎 같은 현부가 있다··························································································· 229. 털여뀌

15. 잎집은 현부가 없다.

16. 식물체에 갈색 털과 대가 있는 선모가 있다.

17. 잎은 심장저이며 소화정에 관절이 있다   ···············································································227. 가시여뀌

17. 잎은 예저이며 선점이 있고 소화경에 관절이 없다   ··································································230. 기생여뀌

16. 식물체에 선모가 없다.

18. 잎집 끝에 털이 없다.

19. 잎자루는 잎집의 중앙 이상까지 붙어 있다   ··········································································231. 물여뀌

19. 잎자루는 잎집 기부에 붙어 있다.

20. 마디가 높고 화수는 길이 10 cm로서 밑으로 처져 있다····························································232. 흰여뀌

20. 마디가 특히 높지 않고 화수는 길이 5cm 이내로서 서 있다 ····················································233. 큰개여뀌

18. 잎집 끝에 털이 있다.

21. 재배식물이다  ·················································································································· 234. 쪽

21. 야생식물이다.

22. 지하경이 길고 화피에 선점이 있다.

23. 꽃은 희고 열매는 윤채가 난다 ··················································································· 235. 흰꽃여뀌

23. 꽃은 붉고 열매는 윤채가 없다  ····················································································· 236.꽃여뀌

22. 지하경이 없는 1 ~2 년초이다.

24. 화피에 선점이 많다.

25. 수과는 렌즈형이고 줄기에 털이 없으며 잎에 검은반점이 없고 매운맛이 난다   ····························· 237. 여뀌

25. 수피는 3릉형이고 줄기에 털이 있으며 잎에 검은 반점이 있고 매운 맛이 없다   ······················· 238. 바보여뀌

24. 화피에 선점이 없거나 극히 적다.

26. 꽃줄기와 위쪽 마디 근처에 점질이 있다 ··································································· 239.끈끈이여뀌

26. 식물체에 점질이 없다.

27. 잎집 끝의 털은 잎집 길이의 1/4 미만이다 ···································································240. 봄여뀌

27. 잎집 끝의 털은 잎집 길이의 1/3 이상이다.

28. 잎은 난형, 넓은 피침형 때로는 피침형이다.

29. 그늘에서 자라며 잎은 녹색이고 길게 뾰족하며 꽃은 담홍색이고 드문드문 달린다  ··········· 241. 장대여뀌

29. 초지나 밭에서 자라며 잎은 짙은 녹색이고 털이 없으며 꽃은 홍색이고배게 달린다  ············ 242. 개여뀌

28. 잎은 좁은피침형, 피침형 또는 선형이다.

30. 화수는 꽃이 드물게 달려서 밑으로 처지고 밑에서는 옆에서도 나온다.

31. 잎은 다소 두꺼우며 마르면 적갈색이 되고 뒷면에 선점이 있다   ······················ 243. 만주겨이삭여뀌

31 잎은 얇으며 녹색으로 마르고 선점이 없다  ····················································· 246. 겨이삭여뀌

30. 화수는 꽃이 밀생하며 곧추서고 옆에서 나오지 않는다.

32. 잎은 뒷면에 선점이 있고 꽃은 밝은 홍색이다   ············································· 244. 붉은대동여뀌

32. 잎에 선점이 없고 꽃은 붉은빛이 돈다  ·····························································245. 대동여뀌