층층나무과 Cornaceae

1. 꽃은 주로 양성이나 때로 단성도 있으며 화피와 수술은 4~5수이고 열매는 핵과 또는 장과이다. 우리나라에는 2속 8종이 있으며 그중에서 식나무속은 1390. 식나무 1종이 자라고 있다.

층층나무속 Cornus LINN.

1. 교목 또는 관목이다.

2. 꽃차례에 큰 포가 있고 열매에 소과경이 없다 ················································································· 1391. 산딸나무

2. 열매에 소과경이 있다.

3. 꽃은 희고 열매는 검거나 희다.

4. 잎은 호생한다 ················································································································· 1392. 층층나무

4. 잎은 대생한다.

5. 가지는 붉고 열매는 희다 ······························································································· 1393. 흰말채나무

5. 열매는 검게 익는다.

6. 잎은 측맥이 4~5쌍이고 가지는 나중에 자줏빛으로 변하며 꽃차례는 윗면이 편평하다························· 1394. 말채나무

6. 잎은 측맥이 6~10쌍이고 가지는 황갈색 또는 적갈색으로 변하며 꽃차례는 끝이 둔하다······················ 1395. 곰의말채

3. 꽃은 황색이고 열매는 검거나 회다 ······························································································· 1396. 산수유

1. 반관목이며 꽃차례에 흰 포가 있다 ······························································································· 1397. 풀산딸나무