Dogwood

Cornus is a genus of about 30–60 species of woody plants in the family Cornaceae, commonly known as dogwoods, which can generally be distinguished by their blossoms, berries, and distinctive bark. Most are deciduous trees or shrubs, but a few species are nearly herbaceous perennial subshrubs, and a few of the woody species are evergreen. Several species have small heads of inconspicuous flowers surrounded by an involucre of large, typically white petal-like bracts, while others have more open clusters of petal-bearing flowers. The various species of dogwood are native throughout much of temperate and boreal Eurasia and North America, with China and Japan and the southeastern United States particularly rich in native species.

Species include the common dogwood Cornus sanguinea of Eurasia, the widely cultivated flowering dogwood (Cornus florida) of eastern North America, the Pacific dogwood Cornus nuttallii of western North America, the Kousa dogwood Cornus kousa of eastern Asia, and two low-growing boreal species, the Canadian and Eurasian dwarf cornels (or bunchberries), Cornus canadensis and Cornus suecica respectively.

Depending on botanical interpretation, the dogwoods are variously divided into one to nine genera or subgenera; a broadly inclusive genus Cornus is accepted here, with four subgenera.

Common name "dogwood"

The name "dog-tree" entered the English vocabulary before 1548, becoming "dogwood" by 1614. Once the name dogwood was affixed to this kind of tree, it soon acquired a secondary name as the Hound's Tree, while the fruits came to be known as dogberries or hound berries (the latter a name also for the berries of black nightshade, alluding to Hecate's hounds). Another theory advances the view that "dogwood" was derived from the Old English dag wood, from the use of the slender stems of its very hard wood for making "dags" (daggers, skewers, and arrows). Another, earlier name of the dogwood in English is the whipple-tree. Geoffrey Chaucer uses "whipple-tree" in The Canterbury Tales ("The Knight's Tale", verse 2065) to refer to the dogwood. A whipple-tree is an element of the traction of a horse-drawn cart, linking the draw pole of the cart to the harnesses of the horses in file; these items still bear the name of the tree from which they are commonly carved.

Characteristics

Dogwoods have simple, untothed leaves with the veins curving distinctively as they approach the leaf margins. Most dogwood species have opposite leaves, while a few, such as Cornus alternifolia and C. controversa, have their leaves alternate. Dogwood flowers have four parts. In many species, the flowers are borne separately in open (but often dense) clusters, while in various other species (such as the flowering dogwood), the flowers themselves are tightly clustered, lacking showy petals, but surrounded by four to six large, typically white petal-like bracts.

The fruits of all dogwood species are drupes with one or two seeds, often brightly colorful. The drupes of several species in the subgenera Cornus and Benthamidia are edible. Many are without much flavor. Cornus kousa and Cornus mas are sold commercially as edible fruit trees. The fruits of Cornus kousa have a sweet, tropical pudding like flavor in addition to hard pits. The fruits of Cornus mas are both tart and sweet when completely ripe. They have been eaten in Eastern Europe for centuries, both as food and medicine to fight colds and flus. They are very high in vitamin C. However, those of species in subgenus Swida are mildly toxic to people, though readily eaten by birds.

Dogwoods are used as food plants by the larvae of some species of butterflies and moths, including the Emperor moth, the Engrailed, thesmall angle shades, and the following case-bearers of the genus Coleophora: C. ahenella, C. salicivorella (recorded on Cornus canadensis), C. albiantennaella, C. cornella and C. cornivorella, with the latter three all feeding exclusively on Cornus.

Uses

Dogwoods are widely planted horticulturally, and the dense wood of the larger-stemmed species is valued for certain specialized purposes. Cutting boards and other fine turnings can be made from this fine grained and beautiful wood. The red seeds are used by over 32 different varieties of game birds to feed upon, including quail.

Horticulture

Various species of Cornus, particularly the flowering dogwood (Cornus florida), are ubiquitous in American gardens and landscaping;horticulturist Donald Wyman stated, "There is a dogwood for almost every part of the U.S. except the hottest and driest areas". In contrast, in England the lack of sharp winters and hot summers makes Cornus florida very shy of flowering.

Many species in subgenus Swida are stoloniferous shrubs that grow naturally in wet habitats and along waterways. Several of these are used along highways and in naturalizing landscape plantings, especially those species with bright red or bright yellow stems, particularly conspicuous in winter, such as Cornus stolonifera.

Most of the species in subgenus Benthamidia, including the flowering dogwood, are small trees useful as ornamental plants. When flowering, they are of rare elegance and beauty, comparable to Carolina silverbell, Canadian serviceberry, and the Eastern redbud for their ornamental qualities.

Fruits

The species Cornus mas is commonly cultivated in southeastern Europe for its edible berries, which can be turned into jam, fermented into a wine, or eaten raw after slight bletting.

Wood

Dense and fine-grained, dogwood timber has a density of 0.79 and is highly prized for making loom shuttles, tool handles, roller skates and other small items that require a very hard and strong wood. Though it is tough for woodworking, some artisans favor dogwood for small projects such as walking canes, arrow making, mountain dulcimers and fine inlays. Dogwood wood is an excellent substitute for persimmon wood in the heads of certain golf clubs ("woods"). Dogwood lumber is rare in that it is not readily available with any manufacturer and must be cut down by the person(s) wanting to use it.

Larger items have also been occasionally made of dogwood, such as the screw-in basket-style wine or fruit presses. The first kinds of laminated tennis rackets were also made from this wood, cut into thin strips.

Dogwood twigs were used by pioneers to brush their teeth. They would peel off the bark, bite the twig and then scrub their teeth.

Classification

Dogwoods are grossly distinguished by the relative conspicuousness of their flowers and bracts (involucres). The following classification recognizes a single, inclusive genus Cornus, with four subgenera. Synonyms are given to provide equivalent names if these subgenera are recognized instead as the separate genera Benthamidia, Chamaepericlymenum, and Swida, in addition to a more narrowly taken Cornus, and also for a five-genus classification, in which Dendrobenthamidia is distinguished from a more narrowly taken Benthamidia. Note that the four species in the subgenus Cornus below retain the same names regardless of whether these additional genera are separately recognized. In a few cases, when a species listed here is sometimes separated instead into two species, that additional name is also listed, with the notation "here including...".

Geographical ranges as native plants are given below. In addition, cultivated species occasionally persist or spread from plantings beyond their native ranges, but are rarely if ever locally invasive.

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