현삼과 Scrophulariaceae

1. 상순은 봉오리 안에서 1~2 개의 측열편으로 싸여 있다.

2. 꽃부리는 양순형이며 상순은 투구형이거나 곧추서고 하순은 퍼진다.

3. 종자는 1-4 개씩이고 길이 2~4mm 이며 잎은 대생하고 반기생식물이다 ···················································며느리밥풀속

3. 종자는 보다 작고 많다

4. 다년초로서 삭과는 이그러지고 편평하며 한쪽으로 터진다 ······································································송이풀속

4. 반기생 1，2 년초이다.

5. 꽃받침 밑에 소포가 2 개 있다 ·································································································347. 절국대

5. 꽃받침 밑에 소포가 없다.

6. 우상복엽이며 선모가 많고 종자에 그물무늬가 있다································································359. 나도송이풀

6. 잎은 톱니가 있거나 손바닥모양으로 갈라진다.

7. 수상화서로 달라며 꽃받침은 비슷하게 4 개로 갈려지고 포가 잎에 비하여 크다 ···································· 좁쌀풀속

7. 총상화서가 원추상으로 되며 꽃받침잎은 크기가 다르다 ··························································358. 쌀파도풀

2. 꽃부리의 열편은 퍼지거나 다소 양순형이 되어도 열편이 편평하다.

8. 1 년초로서 꽃은 잎겨드랑이에 1 개씩 달리고 황색이다········································································324. 성주풀

8. 다년초로서 꽃은 남자색 또는 백색이며 수상 또는 총상으로 달린다

9. 꽃부리는 통부가 열편보다 훨씬 길다 ································································································344. 냉초

9. 꽃부라는 수레바퀴같이 퍼지며 통부가 짧다

             10. 꽃은 총상 및 수상화서에 달린다 ································································································ 꼬리풀속

             10. 꽃은 잎겨드랑이에 1 개씩 달라며 전체가 수상으로된다  ································································· 개불알풀속

1. 상순은 봉오리 안에서 측열편을 감싼다

11. 꽃부리 기부에 주머니 또는 거가 있다.

12. 꽃부리 기부에 주머니가 있다   ······································································································320. 금어초

12. 꽃부리 기부에 거가 있다  ················································································································해란초속

11. 꽃부리 기부에 주머니 또는 거가 없다.

13. 원추상 화서이며 삭과는 포 사이에서 터진다  ······························································································현삼속

13. 꽃차례는 단순하며 밑에서부터 핀다.

14. 포복경은 옆으로 벋으며 마디에서 잎이 총생한다   ··············································································306. 등포풀

14. 잎은 대생하거나 윤생한다.

15. 꽃은 황색이고 꽃받침은 통형이며 능선이있다 ············································································ 물꽈리아재비속

15. 꽃은 담자색 또는 백색이다.

16. 앞쪽 1 쌍의 수술은 꽃부리 통부에 달리며 완전하거나 또는 불완전하다.   ··················································  외풀속

16. 앞쪽 1 쌍의 수술은 꽃부리 통부에 달라며 때로는 없기도 하다.

17. 완전한 수술은 4개이다.

18. 수생식물로서 잎의 뒷면에 선점이 있고 꽃은 잎겨드랑이에 1 개씩달린다.  ··········································구와말속

18. 잎의 뒷면에 산점이 없고 꽃은 짧은 총상화서에 달린다.

19. 꽃부리는 봉오리 안에서 상순이 하순을 감싼다   ·······································································주름잎속

19. 꽃부리는 봉오리 안에서 하순이 상순을 감싼다.

20. 꽃받침은 통성이며 꽃부리의 열편 길이는 비슷하다    ·····························································346. 지황

20. 꽃받침은 밑까지 갈라지며 꽃부리는 하순의 중앙열편이가장길다   ······································345. 디기탈리스

17. 완전한 수술은 2 개이다.

21 꽃받침은 통상이고 얕게 갈라지며 5 개의 능선이 있고 꽃부리통은 짧으며 열편이퍼진다  ······················· 315. 진흙풀

21. 꽃받침은 깊게 또는 완전히 갈라지며 꽃부리는 통부가 있고 양순형이다

22. 잎은 모두 같으며 뿌리애서 돋은 잎이 없다.

23. 꽃받침잎은 포개지며 밑에 소포가 있고 꽃밥에 털이 없다 ·················································· 316. 큰고추풀

23. 꽃받침잎은 마주 닿으며 밑에소포가 없고 꽃밥에 털이 있다. ················································진땅고추풀속 

22. 뿌리에서 돋은 잎이 있고 줄기에 달린 잎은 비늘처럼 작다 ························································319. 등에풀

오동나무속 Pαulownia S. et Z.

1. 잎 뒤에 담갈색털이나 흰 털이 있고 꽃에 자줏빛 점이 있다   ········································································ 299. 참오동

1. 잎 뒤에 다갈색 털이 있고 꽃잎에 자색 점이 없거나 희미한 점이 있다.

2. 자색 점이 없다   ···························································································································· 300. 오동

2. 꽃부려통에 희미한 점이 있다   ···································································································· 300+. 충무오동