층층나무과(層層--科, 학명: Cornaceae 코르나케아이)는 층층나무목의 과이다. 온대지역에 분포하며, 현재의 분류 기준으로 2속 약 85종 가량이며, 한국에는 박쥐나무, 층층나무, 말채나무, 산딸나무, 산수유 등 2속 8종이 분포하고 있다. 박쥐나무속을 박쥐나무과로 따로 분류했었으나, AGP II 체계에서 층층나무과로 통합되었으며 9개속이 층층나무목에서 빠졌다. 연구에 따라 더하고 빼기가 빈번하여 한 연구원은 이 과를 "dustbin"(휴지통과)라고 까지한 실정이다. 대부분은 교목이지만 종에 따라서는 초본인 것도 있다. 잎은 마주나거나 어긋나며 잎자루가 있고 모양은 단순하며 가장자리가 매끈하다. 꽃은 보통 여러 개가 모여서 총상으로 달리지만, 때로는 더 촘촘히 모여 산형꽃차례처럼 되기도 하며, 또 돌매화나무속에서는 두상꽃차례가 되기도 한다. 각각의 꽃은 작으며, 4-5개씩의 꽃받침조각·꽃잎·수술을 가진다. 씨방은 하위로, 꽃받침통과 서로 붙어 있는데, 그 안은 1-4개의 방으로 이루어져 있으며, 각 방에는 1개의 밑씨가 만들어진다. 열매는 공 모양의 핵과이다.

박쥐나무속(Alangium Lam.)

Alangium alpinum (C.B.Clarke)

Alangium barbatum (R. Br.) Baill.

Alangium chinense (Lour.) Harms

Alangium faberi Oliv.

Alangium grisolleoides Capuron

Alangium javanicum (Blume) Wangerin

Alangium kurzii Craib

Alangium kwangsiense Melch.

Alangium longiflorum Merr.

단풍박쥐나무 Alangium platanifolium

박쥐나무 Alangium platanifolium var. trilobum

Alangium salviifolium (L.f.) Wangerin

Alangium villosum (Blume) Wangerin

Alangium vitiense (A.Gray) Baill. ex Harms

Alangium yunnanense C.Y.Wu

층층나무속(Cornus L.)

곰의말채나무(Cornus macrophylla Wall.)

말채나무(Cornus walteri F.T.Wangerin)

산딸나무(Cornus kousa F.Buerger ex Hance)

산수유(Cornus officinalis Siebold & Zucc.)

유럽말채나무(Cornus sanguinea L.)

층층나무(Cornus controversa Hemsl.)

풀산딸나무(Cornus canadensis L.)

흰말채나무(Cornus alba L.)

태평양층층나무(Cornus nuttallii Audubon)

Subgenus Yinquania. Leaves opposite to subopposite; fall blooming.

Cornus oblonga.

Cornus peruviana. Costa Rica and Venezuela to Bolivia.

Subgenus Kraniopsis. Leaves opposite; summer blooming.

Cornus alba (Siberian dogwood). Siberia and northern China.

Cornus amomum (silky dogwood). Eastern U.S. east of the Great Plains except for the Deep South.

Cornus asperifolia (toughleaf dogwood). Southeastern U.S.

Cornus austrosinensis (South China dogwood). East Asia.

Cornus bretschneideri (Bretschneider's dogwood). Northern China.

Cornus coreana (=Cornus walteri) Korean dogwood. Northeast Asia.

Cornus drummondii (roughleaf dogwood). U.S. between the Appalachia and the Great Plains, and southern Ontario, Canada.

Cornus excelsa.

Cornus foemina (stiff dogwood) Southeastern and southern United States.

Cornus glabrata (brown dogwood or smooth dogwood). Western North America.

Cornus hemsleyi (Hemsley's dogwood). Southwest China.

Cornus koehneana (Koehne's dogwood). Southwest China.

Cornus macrophylla (large-leafed dogwood; Chinese: 梜椋; pinyin: jiáliáng or jiàliáng). East Asia.

Cornus obliqua (pale dogwood). Northeastern and central U.S., and southeastern Canada.

Cornus paucinervis. China.

Cornus racemosa (northern swamp dogwood or gray dogwood). Northeastern and central U.S., and extreme southeastern Canada.

Cornus rugosa (round-leaf dogwood). Northeastern and north-central U.S., and southeastern Canada.

Cornus sanguinea (common dogwood). Europe.

Cornus sericea (red osier dogwood). Northern and western North America, except Arctic regions.

Cornus walteri (Walter's dogwood). Central China.

Cornus wilsoniana (ghost dogwood). China.

Cornus × arnoldiana (Hybrid: C. obliqua × C. racemosa). Eastern North America.

Subgenus Mesomora. Leaves alternate; summer blooming.

Cornus alternifolia (pagoda dogwood or alternate-leaf dogwood). Eastern U.S. and southeastern Canada.

Cornus controversa (table dogwood). East Asia.

Subgenus Afrocrania. Dioecious, bracts 4.

Cornus volkensii.

Subgenus Cornus. Plants hermaphroditic, bracts 4 or 6

Cornus eydeana.

Cornus mas (European cornel or Cornelian-cherry). Mediterranean.

Cornus officinalis (Japanese cornel). China, Japan, Korea.

Cornus sessilis (blackfruit cornel). California.

Subgenus Sinocornus. Plants hermaphroditic, bracts 4 or 6

Cornus chinensis (Chinese cornel). China.

Subgenus Discocrania. Bracts 4, modified, non-petaloid; fruits oblong, red.

Cornus disciflora.

Subgenus Cynoxylon. Bracts 4 or 6, large and petaloid, fruits oblong, red.

Cornus florida (flowering dogwood). U.S. east of the Great Plains, north to southern Ontario.

Cornus nuttallii (Pacific dogwood). Western North America, from British Columbia to California.

Subgenus Syncarpea. Bracts 4, large and petaloid, fruits red, fused into a compound multi-stoned berry.

Cornus capitata (Himalayan flowering dogwood). Himalaya.

Cornus elliptica

Cornus hongkongensis (Hong Kong dogwood). Southern China, Laos, Vietnam.

Cornus kousa (Kousa dogwood). Japan and (as subsp. chinensis) central and northern China.

Cornus multinervosa.

Subgenus Arctocrania.

Cornus canadensis (Canadian dwarf cornel or bunchberry) Northern North America, southward in the Appalachian and Rocky Mountains.

Cornus suecica (Eurasian dwarf cornel or bunchberry). Northern Eurasia, locally in extreme northeast and northwest North America.

Cornus × unalaschkensis (Hybrid: C. canadensis × C. suecica). Aleutian Islands (Alaska), Greenland, and Labrador and Newfoundland in Canada.

Horticultural hybrids

Cornus × rutgersensis (Hybrid: C. florida × C. kousa). Horticulturally developed.