느릅나무속 Ulmus LINN.

1. 열매는 가을에 익는다. 잎은 털이 없고 톱니는 단순하다 ······································································· 114.참느릅나무

1. 열매는 봄에 익는다. 잎은 뒷면에 털이 있는것도 있고 톱니는 겹톱니이다.

2. 잎은 피침형 또는 장타원형이며 털이 없고 밋밋하다  ·········································································· 115. 비술나무

2. 잎은 도란형, 도란상 타원형 또는 타원형이며 뒷면에 털이 있고 거칠다.

3. 열매는 길이 2~3cm 로서 털이 있다   ························································································116. 왕느릅나무

3. 열매는 길이 1.5 cm 미만이다.

4. 잎 끝은 결각상이다  ··········································································································· 118. 난티나무

4. 잎 끝은 결각상이 아니다.

5. 잎은 도란형이며 뒷면에 털이 있고 길이 7~18cm 이다  ···························································117. 큰잎느릅나무

5. 잎은 도란상 타원형이며 길이 8cm 내외이다.

6. 열매는 중앙에 털이 있다   ····························································································· 119. 당느릅나무

6. 열매는 털이 없다 ········································································································ 119+. 느릅나무