C. alba 'Argenteo-marginata'
C. alba 'Sibirica'
C. sericea, also called C. stolonifera
C. sericea 'Flaviramea'
Dogwoods make up the family Cornaceae, in the order Cornales. The bunch berry is classified as Cornus canadensis, the pagoda dogwood as Cornus alternifolia, the flowering dogwood as Cornus florida, the Pacific dogwood as Cornus nuttalli, the Cornelian cherry as Cornus mas, the red-osier dogwood as Cornus stolonifera, the Japanese dogwood as Cornus kousa, and the blood-twig dogwood as Cornus sanguinea. The sour gums commonly found in cultivation are classified in the genus Nyssa, in the family Nyssaceae. The two other families in the order Cornales are Alangiaceae and Garryaceae.
Dogwood, common name for a family of flowering plants distributed mainly in the temperate areas of the northern hemisphere, with a few species occurring in tropical South America and Africa. Of the 14 genera in the family, only the dogwood genus is native to North America. Members of the family are mostly trees or shrubs with simple, opposite leaves. Well-known exceptions, however, are the bunch berry, a perennial herb; and the pagoda dogwood, which has alternate leaves. Dogwood flowers are small and are produced in branched terminal clusters that are sometimes surrounded by showy white bracts. Thus, the so-called petals of the familiar flowering dogwood are actually bracts.
Dogwoods are deciduous ornamental trees that grow from 15 to 40 feet and are generally wider than they are tall. They have year-round interest: flowers in spring, fruit in summer; wine-colored foliage in autumn and a picturesque silhouette in winter. Dogwoods usually grow from 6 to 8 feet to 12 to 15 feet with an equal spread in about five years. They have single or multiple trunks, and mature trees usually take on a flat-topped appearance.
Nearly all dogwoods flower briefly in early spring, and the blooms of the Cornelian cherry are especially prized. After they have flowered, dogwoods produce blue, red or white berries that attract wild birds.
The order to which the dogwoods belong contains 4 families and about 150 species, about 100 of which are in the same family as dogwoods. The sour gum family contains three genera. The two other families both contain one genus. Members of the order vary greatly in flower structure, making the order difficult to characterize. The flowers are usually small, however, with the four or five sepals commonly reduced in size and forming a tube that is fused to the ovary (female flower part). A nectar-producing disk is usually present on the upper part of the ovary. Four or five petals are commonly found; they are not fused to one another. Occasionally, however, the petals are absent.