낙우송과 Taxodiaceae

1. 상록수이다.

2. 잎은 2 개가 합쳐져 두껍고 끝이 파졌으며 단지 끝에 15-40 개가 윤생한다······················································ 256. 금송

2. 잎은 합쳐지지 않고 총생한다.

3. 잎은 송곳같이 뾰족하고 굽었다 ··································································································· 259. 삼나무

3. 잎은 피침형이며 편평하고 뒷면이 회청색이다 ·········································································· 260. 넓은잎삼나무

1. 낙엽수이며 잔가지는 겨울에 떨어진다.

4. 잎은 대생한다   ················································································································· 258. 메타세쿼이아

4. 잎은 호생한다  ·························································································································· 257. 낙우송