Ivy

Plant Characteristics

Cultivation

Scientific Names

Read about Ivy in the Standard Cyclopedia of Horticulture

Hedera (ancient Latin name of the ivy). Araliaceae. Ivy. Ornamental woody rootnclimbing vines grown for their handsome persistent foliage. Evergreen shrubs, climbing by aerial rootlets: lvs. alternate, long-petioled, entire or coarsely dentate or 3-7-lobea: fls. perfect, pedicelled, in umbels arranged in terminal racemes or panicles; calyx 5-toothed; petals and stamens 5; ovary 5-celled; style short, cylindric: fr. a 3-5-seeded berry.—Five species (or 6, if H. helix chrysocarpa is considered a distinct species) in Eu., N. Afr. and from W. Asia through Cent. Asia to Japan. Monograph by Fr. Tobler, Die Gattung Hedera (1912); a good popular monograph is Shirley Hibberd's "The Ivy: A monograph, comprising the history, uses, characteristics, and affinities of the plant, and a descriptive list of all the garden ivies in cultivation." London, 1872. Many araliads have been described formerly as species of Hedera which are now referred to other genera. The ivies are climbing shrubs, with inconspicuous greenish flowers appearing in fail, and black, rarely yellow, red or whitish berries ripening the following spring. Hedera helix is hardy in sheltered places as far north as Massachusetts; at the Arnold Arboretum a form introduced from the Baltic provinces. Russia, under the name H. helix baltica has proved hardier than any other form. All other species, also most of the variegated forms of H. helix and its var. hibernica, are tender, but the Japanese species has not yet been sufficiently tested. The ivy is a very valuable plant for covering walls, rocks, trunks of trees and trellis-work, and sometimes climbs very high. It may also be used for covering walls in cool greenhouses, for screens in drawing- rooms and for hanging-baskets. It is a popular window-garden plant, enduring many uncongenial conditions and thriving without bright sunlight. In shady places under trees it makes a handsome evergreen caret, and is also often used for borders of shrubberies or flower-beds. It grows in almost any soil, but best in a somewhat moist and rich one, and in shaded positions. The climbing or creeping branches do not flower; flowers are produced on erect, bushy branches, appearing on old, high-climbing plants only. Propagation* is by cuttings of half-ripened wood at any time of the year in the greenhouse or in frames, or, in more temperate regions, in the open ground in fall; gentle bottom heat will hasten the development of roots considerably; also increased by layers and by seeds which must be sown soon after ripening and germinate slowly, usually not until the second year. The slow-growing forms, especially the shrubby ones, are often grafted on cuttings of strong-growing varieties, as they do not grow readily from cuttings. H. glomerulata, DC., belongs to the genus Brassaiopsis and its correct name is B. glomerulata, Hegel {B. speciosa, Decne. & Planch.). A glabrous tree, with large digitate lvs.; lfts. 5-7, oblong-lanceolate, stalked: fls. in long pendulous panicles consisting of long-stalked globular heads of small Ms. S. Asia. H.M. 4804. Gt. 12:411. G.M. 32:367.—H. himalaica. Tobler (H. helix aurantiaca, Andre). High-climbing: pubescence scaly, gray or yellowish, the scales with many rays: lvs. of the sterile branches pinnately lobed with 2-5 lobes or teeth on each side, those of the flowering branches oblong-ovate to oblong-lanceolate, cuneate at the base: fr. yellow. Himalayas. H.H. 1884:84. Var. sinensis, Tobler. Lvs. of sterile shoots entire or 3-iobed, of fertile branches elliptic or elliptic-oblong. W. China. H. japonica, Tobler (H. helix var. rhombea, Sieb. & Zucc.). Not high-climbing: scales of pubescence with many rays: lvs. elliptic-ovate to rhombic-ovate, those of the sterile shoots 3- or rarely 5-lobed, with broad middle lobe and small lateral lobes: fr. black, about 1/3 in. or less across. Japan, Korea- Alfred Rehder. The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.

? Hedera
Hedera hibernica shoot with flower buds
Plant Info
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Apiales Family: Araliaceae Subfamily: Aralioideae Genus: Hedera L.
Species
*Hedera algeriensis – Algerian Ivy Hedera azorica – Azores Ivy Hedera canariensis – Canaries Ivy Hedera caucasigena Hedera colchica – Caucasian Ivy Hedera cypria Hedera helix – Common Ivy Hedera hibernica – Irish Ivy Hedera maderensis – Madeiran Ivy Hedera maroccana Hedera nepalensis – Himalayan Ivy Hedera pastuchowii – Pastuchov's Ivy Hedera rhombea – Japanese Ivy Hedera sinensis Hedera taurica

Hedera (English name ivy, plural ivies) is a genus of 15 species of climbing or ground-creeping evergreen woody plants in the family Araliaceae, native to the Atlantic Islands, western, central and southern Europe, northwestern Africa and across central-southern Asia east to Japan. On suitable surfaces (trees and rock faces), they are able to climb to at least 25–30 metres above the basal ground level.

They have two leaf types, with palmately lobed juvenile leaves on creeping and climbing stems, and unlobed cordate adult leaves on fertile flowering stems exposed to full sun, usually high in the crowns of trees or the top of rock faces. The juvenile and adult shoots also differ, the former being slender, flexible and scrambling or climbing with small roots to affix the shoot to the substrate (rock or tree bark), the latter thicker, self-supporting, and without roots. The flowers are produced in late autumn, individually small, in 3–5 cm diameter umbels, greenish-yellow, and very rich in nectar, an important late food source for bees and other insects; the fruit are small black berries ripening in late winter, and are an important food for many birds, though poisonous to humans. The seeds are dispersed by birds eating the fruit. The leaves are eaten by the larvae of some species of Lepidoptera such as Angle Shades, Lesser Broad-bordered Yellow Underwing, Scalloped Hazel, Small Angle Shades, Small Dusty Wave (which feeds exclusively on ivy), Swallow-tailed Moth and Willow Beauty.

Taxonomic note

The species are largely allopatric and closely related, and all have on occasion been treated as varieties or subspecies of H. helix, the first species described. Several additional species have been described in the southern parts of the former Soviet Union, but are not regarded as distinct by most botanists.

Uses and cultivation

Ivies are very popular in cultivation within their native range, both for attracting wildlife, and for their evergreen foliage; many cultivars with variegated foliage and/or unusual leaf shape have been selected. They are particularly valuable for covering unsightly walls. Ivies have however proved to be a serious invasive weed in the parts of North America where winters are not severe, and their cultivation there is now discouraged in many areas. Similar problems exist in Australia where the plant was originally cultivated in gardens.

Much has been argued as to whether ivy climbing trees will harm the tree or not; the consensus in Europe is that they do not harm trees significantly, though they may compete for ground nutrients and water to a small extent, and trees with a heavy growth of ivy can be more li able to windthrow. Problems are greater in North America, where trees may be overwhelmed by the ivy to the extent they are killed; this could be because ivy in North America, being introduced, is without the natural pests and diseases that control its vigour in its native areas. A more serious problem is that ivy creates a vigorous, dense, shade-tolerant evergreen groundcover (precisely the characteristics for which it is often cultivated) that can spread over large areas and outcompete native vegetation.

Similar concerns are expressed about damage to walls. It is generally considered that a soundly mortared wall is impenetrable to the climbing roots of ivy and will not be damaged, and is also protected from further weathering by the ivy keeping rain off the mortar. Walls with already weak or loose mortar may however be badly damaged, as the ivy is able to root into the weak mortar and further break up the wall. Subsequent removal of the ivy can be difficult, and is likely to cause more damage than the ivy itself. Modern mortars that contain portland cement and little lime are stronger than older mortar mixes that were largely composed of just sand and lime. Most mortar mixes changed to contain portland cement in the 1930s. Soft mortar is still used when laying softer brick.

Regional English names for ivy include Bindwood and Lovestone (for the way it clings and grows over stones and brickwork).

See also

• Poison ivy - unrelated to this genus

References

• McAllister, H. (1982). New work on ivies. Int. Dendrol. Soc. Yearbook 1981: 106-109.

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  Hedera helix leaves

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  Hedera helix berries

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  Hedera hibernica fruit

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  Hedera colchica flowers

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  Hedera colchica foliage

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  Variegated Ivy

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  Tempelherrenhaus Weimar