가지속 Solanum LINN.

1. 식물체는 곧게 자란다.

2. 잎은 복엽이다.

3. 식물체에 가시가 없다    ················································································································ 281. 감자

3. 식물체에 가시가 있다 ········································································································ 284. 노랑바늘가지

2. 잎은 단엽이다

4. 식물체에 가시가 없다.

5. 식물체에 털이 없다 ·································································································· 283. 까마중(까마종이)

5 식물체에 털이 있다.

6. 재배식물이다 ······················································································································ 282. 가지

6. 야생식물이다.

             7. 식물체전체에털이있다 ··································································································· 283++. 털까마중

7. 꽃술에만 털이 있다 ···································································································· 283+. 미국까마중

4. 식물체에 가시가 있다 ······································································································ 283+++. 도깨비가지

1. 식물체는 덩굴성이다.

8. 꽃은 희고 전체에 다세포 털이 있다   ··································································································285. 배풍등

8. 꽃은 담자색이고 거의 털이 없다   ······························································································286. 좁은잎배풍등