1	"Plant a low herb"	"Cornus canadensis"
1	"Plant a shrub or small tree"	2
2	"Flower clusters with an involucre of petal-like bracts (occasionally no longer than the flowers)"	3
2	"Flower clusters without an involucre of bracts"	8
3	"Involucral bracts small and yellowish, not longer than the flowers"	4
3	"Involucral bracts large, showy, petal-like"	5
4	"Vein pairs 3–5, without tufts of red-brown hairs in the vein axils on lower leaf surface"	"Cornus mas"
4	"Vein pairs 5–7, with tufts of red-brown hairs in the vein axils on lower leaf surface"	"Cornus officinalis"
5	"Fruits in a head but free from one another"	6
5	"Fruits fused together in a fleshy head"	7
6	"Petal-like bracts 4, notched at the tip; fruit scarlet"	"Cornus florida"
6	"Petal-like bracts 4–6, pointed or blunt but not notched; fruit orange-red"	"Cornus nuttallii"
7	"Leaves deciduous, ovate; bracts 4, widest below the middle, white to cream; mature fruit about 2 cm wide"	"Cornus kousa"
7	"Leaves evergreen, oval to oblong or lanceolate; bracts 4–6, widest above the middle, yellow; mature fruit at least 2.5 cm wide"	"Cornus capitata"
8	"Leaves alternate; foliage arranged in tiers"	9
8	"Leaves opposite; foliage not in tiers"	10
9	"Leaves glossy above, hairless below; flower clusters 10–20 cm wide"	"Cornus controversa"
9	"Leaves dull above, hairy below; flower clusters 4–6 cm wide"	"Cornus alternifolia"
10	"Fruits green or black"	"Cornus sanguinea"
10	"Fruit white or blue"	11
11	"Leaves with woolly hair below, at least on the veins or in vein axils"	12
11	"Leaves hairless below or with hair flattened down"	14
12	"Fruits white"	"Cornus stolonifera ‘Baileyi’"
12	"Fruits blue"	13
13	"Leaves grey-hairy below"	"Cornus rugosa"
13	"Leaves with rust-coloured hair on veins below"	"Cornus amomum"
14	"Flower clusters rounded and branched"	"Cornus racemosa"
14	"Flower clusters flat-topped"	15
15	"Stems spreading, stoloniferous; branchlets purplish"	"Cornus stolonifera"
15	"Stems not spreading; branchlets not purplish"	"Cornus alba"