Page:Encyclopædia Britannica, Ninth Edition, v. 13.djvu/550

 526 IVY IVY (A. S., //?/; ; Germ., Epheu ; perhaps connected with opium, O.TTLOV) is the collective designation of certain species FIG. 1. European Ivy (Ifedera Helix). Half nat. size. and varieties of Ifedera, the important alliances of which are Aralia and Panax, which, with some twenty other FIG. 2. Ifedera Helix, var. Deltoidea. Half nat. size. less-known genera, constitute the natural order Araliacese. There are fifty species of ivy recorded in modern books, but FIG. 3. Fruiting Form of Ifedera Helix. Half nat. size. they may be reduced to three. The European ivy is the Hedera Helix of Linnaeus (figs. 1-3), a plant subject to in finite variety in the forms and colours of its leaves, but the tendency of which is always to a three-lobed form when climbing and a regular ovate form of leaf when producing fruit (fig. 3). The African ivy is //. canariensis, Willd. (fig. 4), otherwise known as the Irish ivy, a native of Africa and the adjacent islands. This also varies, but in a less degree than If. Helix, from which its leaves differ in their larger size, rich deep green colour, and a prevailing tendency to FIG. 4. African Ivy (Hedera canariensis}. Half nat. size. a five-lobed outline. When in fruit the leaves are usually three-lobed, but they are sometimes entire and broadly ovate. The Asiatic ivy is //. colchica, Koch (fig. 5), other wise known as If. rxgneriana and If. ragusina. This lias ovate, obscurely three-lobed leaves of a coriaceous texture and a deep green colour ; in the tree or fruiting form the leaves are narrower than in the climbing form, and without any trace of lobes. Distinctive characters are also to be FIG. 5. Asiatic Ivy (lledem colchica). Onu-thir.l nat. size. found in the appendages of the pedicels and calyx, //. Helix having six-rayed stellate hairs, //. canariensis fifteen-rayed hairs, and //. colchica yellowish two-lobed scales. A revision of the natural order He.deracese by the late Dr B. Seemann will be found in the Journal of Botany, 1864-5-6. It is of the utmost importance to note the difference