Cornus kousa is a small deciduous tree 8- tall, in the flowering plant family Cornaceae. Common names include kousa, kousa dogwood,[1] Chinese dogwood,[2] [3] Korean dogwood,[3] [4] [5] and Japanese dogwood.[1] [3] Synonyms are Benthamia kousa and Cynoxylon kousa.[6] It is a plant native to East Asia including Korea, China and Japan.[1] [7] Widely cultivated as an ornamental, it is naturalized in New York State.[8]
Like other Cornus, C. kousa has opposite, simple leaves, 4–10 cm long. The tree is extremely showy when in bloom, but what appear to be four, white petals are actually four spreading bracts below the cluster of inconspicuous yellow-green flowers. The blossoms appear in late spring, weeks after the tree leafs out.
It can be distinguished from the flowering dogwood (Cornus florida) of eastern North America by its more upright habit, flowering about a month later, and by the pointed rather than rounded flower bracts.
The fruit is a globose pink to red compound berry 2–3 cm in diameter, though these berries tend to grow larger towards the end of the season and some berry clusters that do not fall from the tree exceed 4 cm. It is edible, with a sweet and creamy flavour, and is a delicious addition to the tree's ornamental value. The fruit is sometimes used for making wine.[9]
It is resistant to the dogwood anthracnose disease, caused by the fungus Discula destructiva, unlike C. florida, which is very susceptible and commonly killed by it; for this reason, C. kousa is being widely planted as an ornamental tree in areas affected by the disease.[7]
Fall foliage is a showy red color.
There are two recognized subspecies / varieties:
Hybrids between C. kousa and C. florida (Cornus × rutgersensis) and C. kousa and C. florida (Cornus × elwinortonii) have been created by Rutgers University. Several selected for their disease resistance and good flower appearance have been named, patented, and released.[15]
| Cultivar | Bract color | Foliage | Habit | Notes | |
|---|---|---|---|---|---|
| 'Beni Fuji' | The deepest red-pink bracts of any cultivar. | The color may not be as strong in warm summer areas. | |||
| 'Elizabeth Lustgarten' and 'Lustgarten Weeping' | Notable for weeping habit, grow to 15' with branches that arch downwards. | The habit is rounded and gentle, a mature specimen is attractive. | |||
| 'Gold Star' | White | Center of each leaf has a broad gold band, with stems that are somewhat reddish. | Relatively slow-growing, but in time does form a small-medium rounded tree. | The contrast between the red fruit and gold-splashed foliage can be striking. | |
| 'Little Beauty' | Forms a small, densely branched tree that may never exceed 15' tall. | Other traits are as per the species. | |||
| 'Milky Way' | Pure White | Extremely floriferous and sets a very heavy crop of fruit. When in bloom, the bracts can conceal the foliage. | One of the most common cultivars. This chinensis cultivar is probably composed of over a dozen similar clones. | ||
| 'Satomi' or 'Miss Satomi' (also sold as 'Rosabella') | Deep pink bracts. | Leaves turning purple and deep red in autumn. | Spreading medium-sized shrub. | This is a very popular cultivar. Warm summers seem to dull the color and many plants bloom light pink or white-pink. | |
| 'Snowboy' | Sports gray-green leaves that are edged in white, with occasional splashes of variegation throughout the foliage. | Very slow-growing. | The plant is attractive when well grown. Best sited in a shady location to avoid leaf scorch. | ||
| 'Summer Stars' | Blooms heavily and grows to 25' tall with a vase shape. | The flower bracts on this selection are not as large as those of other cultivars, but they are retained longer. | |||
| 'Temple Jewel' | White | Variegated form with leaves that show a light marbling of green, gold and light pink that turns mostly green with age. | Grows well to 20' tall and wider with a dense habit. | ||
| 'Variegata' | Various clones exist with differing degrees of yellow or white variegation. | Most are slower growing. | The pattern may be unstable, plus the plants can produce green growth reversions. It benefits from siting in some shade. | ||
| 'Wolf Eyes' | Variegated form with leaves that show a uniform white margin. The leaf margins are often prominently wavy. In fall, the leaves develop attractive pink to red coloration. | Shrubby and slow-growing, to 10' tall and wide. | This is a very popular cultivar. The variegation pattern is quite stable and resistant to burning. A shaded planting site is desirable. |
, the following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:[17]
C. kousa has edible berries. The soft pulp is sweet with a similar flavour to a ripe persimmon but the presence of hard seeds that are well attached to the pulp can be inconvenient when eaten directly. The rind of the berries is usually discarded because it has a bitter taste, although it is edible. The seeds are usually not eaten, but could be ground into jam and sauces. While less popular than the berries, young leaves can also be consumed.[25] [26]