Ivy, a common name, from the Anglo-Saxon, for species of the genus hedera (Celtic hedra, a cord) of the araliacece, a family which is closely related to the umbelliferce, but different in the structure of its fruit, which has always more than two carpels. The genus hedera consists of evergreen climbing shrubs, with simple leaves and the flowers in umbels. Its most familiar representative is the common or English ivy, IT. helix, a plant which contributes largely to the English landscape, and around which are clustered so much of poetry and legend. This is found all over Britain, in western and southern Europe, western Asia, and northern Africa, but scarcely at all in central Europe. In its wild state the slender lower branches spread upon the ground, while the main stems climb upon trees, buildings, and other supports to a great height, by means of aerial rootlets. The leaves are three- to five-lobed, and of a pleasing dark green color. The plant rarely flowers until it has reached the summit of the support upon which it climbs; it then throws out from the main stem short flowering branches, upon which the leaves are not lobed, like those upon the other steins, but nearly oval; each branch terminates in a sort of panicle of numerous small umbels of yellowish green flowers; these open in early autumn; they are fragrant, and very attractive to bees; the berries, which are black, ripen the following spring.
The ivy climbs to the tops of the tallest trees and surmounts the highest buildings; the largest specimens in England have trunks 10 to 111/2 in. in diameter; it is a very long-lived plant. Ivy formerly enjoyed some medicinal reputation, but it is scarcely used at present; the berries, which to man are emetic and cathartic, are readily eaten by various birds; in warm climates it exudes an aromatic, resinous matter, said to possess stimulant properties. In England the ivy naturally clothes ruins, old trees, and rocky places, and thus forms a prominent feature in the landscape; but besides this it is largely used in gardening, it being employed to cover buildings, to form evergreen walls, and to make screens to hide unsightly objects. In this country ivy cannot be considered as certainly hardy north of Philadelphia; in the sheltered streets of cities like New York it has sometimes attained a large size, to be destroyed by an unusually severe winter; it is not only the severity of the winters at its northern limit that makes it difficult of cultivation, but the direct rays of the sun in the latter part of winter have an injurious effect upon it; hence it succeeds best upon the northern sides of buildings.
In Virginia the plant flourishes luxuriantly, and some fine specimens may be found growing upon the old mansions of that state. In modern gardening ivy has been introduced as a bedding plant; it is grown with its stems prostrate, and as these take root at every joint a dense mat of its peculiar dark green foliage may be readily produced; it is used in the form of broad edgings to flower beds cut in the lawn, as well as to form beds by itself; its darker green contrasted with the light green of the grass produces a fine effect. In the northern states, however, the great use of ivy is for indoor decoration, for which purpose it is unequalled. It is made to run over window frames, over the arch of folding doors, along cornices, around picture frames, or wherever it may be desired. It is also used to form screens, either for windows or for use in various parts of the room; a trellis of the desired form is fixed to a platform, upon which the ivy plants stand in pots or in a suitable box. It is of the easiest propagation, and for after success only care and patience are required. Cuttings may be rooted in the usual way in sand, or a branch several feet long may be made to strike root by surrounding its lower end for several inches with a ball of sphagnum moss, which is to be tied on.
The ball is placed in a jar or other convenient receptacle in which it can be kept constantly moist; when roots have formed, it may then be set in a pot of earth. Ivy requires a rich soil, and while it is growing an abundance of water. The principal care it needs, besides proper watering, is the washing of the foliage; dust accumulates upon the leaves, and must be removed from time to time by means of a damp sponge. It is sometimes attacked by a scale louse, which upon its first appearance should be removed by a blunt knife or other mechanical means. In summer most of the interior ivy decorations are taken outdoors to a partly shaded spot, but those which are very large must remain in place and receive proper care as to light, water, and cleanliness. - The English ivy presents many varieties, differing in the size and form of the leaf, depth of green, color of fruit, etc.; notable among these are several with the foliage beautifully- marked, margined, or veined with white and yellow, known as gold and silver ivies, all of which are very beautiful, but in this country can only be enjoyed under glass. What is known as the tree ivy is propagated from the flowering shoots; it ultimately forms climbing stems.
Irish ivy, so called, is really a native of the Canaries (H. Canariense), and has much larger leaves than the common. These two are all the species recognized by the late Berthold Seeman in an elaborate memoir (" Journal of Botany," vol. ii.) on the genus; and while the catalogues and works on gardening enumerate scores of species, they are believed to be all reducible to these two. Mr. Shirley Hibbard in 1869, in a communication to the Linnsean society, and later in a work entitled " Ivy, its History and Characteristics" (London, 1873), ignoring all former names, has attempted to arrange the garden forms of ivy, and impose a nomenclature which is not likely to be generally adopted. - Among other plants to which the name ivy has been applied are German ivy, a climbing composite (see German Ivy); Colosseum ivy (linaria cymbalaria), a small creeping toad flax; ground ivy (nepeta gle-clwma), a prostrate European labiate, which is not rare as a weed in the older portions of this country, and which before the introduction of hops was used in England to give bitterness to beer, and is also called alehoof; American ivy, more generally known as the Virginia creeper (ampelopsis quinquefolia), which, though a deciduous plant, occupies much the same place in our vegetation that the ivy does in Europe; and poison ivy, a name which with several others is applied to the well known rhus toxicodendron, for which see Sumach.
English Ivy (Hedera helix).