Genus of flowering plants in the family Araliaceae
This article is about plants in the family Araliaceae. For the typographic ornamentation❧, seeFleuron (typography). For Hedera Hashgraph, seeHashgraph.
Hedera, commonly calledivy (pluralivies), is a genus of 12–15 species ofevergreen climbing or ground-creepingwoody plants in the familyAraliaceae, native toWestern Europe,Central Europe,Southern Europe,Macaronesia,northwestern Africa and across central-southernAsia east toJapan andTaiwan. Several species are cultivated as climbing ornamentals, and the nameivy especially denotes common ivy (Hedera helix), known in North America as "English ivy", which is frequently planted to clothe brick walls.
Hedera helix adult leaves and unripe berries in Ayrshire, Scotland
On level ground ivies remain creeping, not exceeding 5–20 cm height, but on surfaces suitable for climbing, includingtrees, naturalrockoutcrops or man-made structures such asquarry rock faces or builtmasonry andwooden structures, they can climb to at least 30 m above the ground. Ivies have twoleaf types, withpalmately 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 tops of rock faces, from 2 m or more above ground. The juvenile and adult shoots also differ, the former being slender, flexible and scrambling or climbing with small aerial roots to affix the shoot to the substrate (rock or tree bark), the latter thicker, self-supporting and without roots. Theflowers are greenish-yellow with five small petals; they are produced inumbels in autumn to early winter and are very rich innectar. Thefruit is a greenish-black, dark purple or (rarely) yellowberry 5–10 mm diameter with one to five seeds, ripening in late winter to mid-spring. The seeds are dispersed by birds which eat the berries.
The species differ in detail of the leaf shape and size (particularly of the juvenile leaves) and in the structure of the leaftrichomes, and also in the size and, to a lesser extent, the colour of the flowers and fruit. Thechromosome number also differs between species. The basic diploid number is 48, while some are tetraploid with 96, and others hexaploid with 144 and octaploid with 192 chromosomes.[2]
Ivies are natives of Eurasia and North Africa, but have been introduced to North America and Australia. They invade disturbed forest areas in North America.[3] Ivy seeds are spread by birds.[3]
A very wide range of invertebrates shelter and overwinter in the dense woody tangle of ivy.[6] Birds and small mammals also nest in ivy.[7] It serves to increase the surface area and complexity of woodland environments.
The following species are widely accepted; they are divided into two main groups, depending on whether they have scale-like or stellate trichomes on the undersides of the leaves:[2][8][9]
Trichomes scale-like
Hedera algeriensis Hibberd – Algerian ivy. Algeria, Tunisia (Mediterranean coast).
Hedera crebrescens M. Bényei-Himmer et M. Höhn - Buda ivy. Central Europe
Hedera helix L. – Common ivy (syn.H. caucasigena Pojark.,H. taurica (Hibberd) Carrière). Europe, and widely introduced elsewhere.
Hedera hibernica (G.Kirchn.) Bean – Atlantic ivy (syn.H. helix subsp.hibernica (G.Kirchn.) D.C.McClint.). Atlantic western Europe.
The species of ivy are largelyallopatric and closely related, and many have on occasion been treated as varieties or subspecies ofH. helix, the first species described. Several additional species have been described in the southern parts of the formerSoviet Union, but are not regarded as distinct by most botanists.
Hybrids have been recorded between severalHedera species, including Atlantic ivy (H hibernica) with common ivy (H helix).[10] Hybridisation may also have played a part in the evolution of some species in the genus.[2] A well-knownhybrid involving ivies is the intergeneric hybrid× Fatshedera lizei, a cross betweenFatsia japonica andHedera hibernica. This hybrid was produced once in a garden in France in 1910 and has never successfully been repeated, the hybrid being maintained in cultivation by vegetative propagation.[11][12]
When the ivy blooms in September it attractshoverflies and other nectar feeders.A variegatedHedera helix cultivar
Ivies are very popular in cultivation within their native range and compatible climates elsewhere, for their evergreen foliage, attracting wildlife, and for adaptable design uses in narrow planting spaces and on tall or wide walls for aesthetic addition, or to hide unsightly walls, fences and tree stumps. Numerouscultivars with variegated foliage and/or unusual leaf shapes have been selected for horticultural use.[11]
Much discussion has involved whether or not ivy climbing trees will harm trees. In Europe, the harm is generally minor although there can be competition for soil nutrients, light, and water, andsenescent trees supporting heavy ivy growth can be liable towindthrow damage.[4] The UK'sWoodland Trust says "Ivy has long been accused of strangling trees, but it doesn’t harm the tree at all, and even supports at least 50 species of wildlife."[6] Harm and problems are more significant inNorth America, where ivy is without the natural pests and diseases that control its vigour in its native continents; the photosynthesis or structural strength of a tree can be overwhelmed by aggressive ivy growth leading to death directly or by opportunistic disease and insect attacks.[14]
Several ivy species have become a seriousinvasive species (invasive exotic) in natural native planthabitats, especially riparian and woodland types, and also a horticulturalweed in gardens of the western and southern regions of North America with milder winters. Ivies create a dense, vigorously smothering, shade-tolerant evergreen groundcover that can spread through assertive underground rhizomes and above-ground runners quickly over large natural plant community areas and outcompete the native vegetation. The use of ivies asornamental plants in horticulture inCalifornia and other states is now discouraged or banned in certain jurisdictions.[15] Drought-tolerantH. canariensis andH. algeriensis and EuropeanH. helix were originally cultivated in garden, park, and highway landscaping, but they have become aggressively invasive in coastal forests and riparian ecosystems, now necessitating costly eradication programs.[16] Similar problems exist inAustralia[citation needed]. Only one species of ivy,H. helix , bears the status of 'declared weed' in Australia; in the Australian Capital Territory, and Western Australia only.[17]
The name ivy derives fromOld Englishifig, cognate with GermanEfeu, of unknown original meaning.[19] The scientific nameHedera is the classical Latin name for the plant.[11] Old regional common names in Britain, no longer used, include "Bindwood" and "Lovestone", for the way it clings and grows over stones and bricks. USPacific Coast regional common names forH. canariensis include "California ivy" and "Algerian ivy". ForH. helix, regional common names include "common ivy" (Britain and Ireland) and "English ivy" (North America).
Like many other evergreen plants, which impressed European cultures by persisting through the winter, ivy has traditionally been imbued with a spiritual significance. It was brought into homes to drive out evil spirits.[6]
InAncient Rome it was believed that a wreath of ivy could prevent a person from becoming drunk, and such a wreath was worn byBacchus, the god of intoxication.[6]
Ivy bushes or ivy-wrapped poles have traditionally been used to advertise taverns in the United Kingdom, and many pubs are still called The Ivy.[20]
The clinging nature of ivy makes it a symbol of love and friendship, there was once a tradition of priests giving ivy to newlyweds,[6] and as it clings to dead trees and remains green, it was also viewed as a symbol of the eternal life of the soul after the death of the body in medieval Christian symbolism.[21]
^abcAckerfield, J, & Wen, J. (2002). A morphometric analysis of Hedera L. (the ivy genus, Araliaceae) and its taxonomic implications.Adansonia sér. 3, 24: 197-212.Full text.Archived 2011-08-08 at theWayback Machine
^abIngham, C.S.; Borman, M.M. (2010). "English Ivy (Hedera spp., Araliaceae) Response to Goat Browsing".Invasive Plant Science and Management.3 (2):178–181.doi:10.1614/ipsm-09-021.1.S2CID86767633.
^abcMitchell, A. F. (1975). "Three Forest Climbers: Ivy, Old Man's Beard and Honeysuckle".Forest Record.102.
^R H Marshall, H A McAllister & J D Armitage (2017), A summary of hybrids detected in the genusHedera (Araliaceae) with the provision of three new names,New Journal of Botany, 7:1, 2-8[1]
^abcHuxley, A., ed. (1992).New RHS Dictionary of Gardening 2: 60. MacmillanISBN0-333-47494-5.
^"Hedera helix".Weeds Australia. Centre for Invasive Species Solutions. Retrieved20 January 2025.
^M. Kobæk-Larsen; L. P. Christensen; W. Vach; J. Ritskes-Hoitinga; K. Brandt (2005). "Inhibitory Effects of Feeding with Carrots or (-)-Falcarinol on Development of Azoxymethane-Induced Preneoplastic Lesions in the Rat Colon".Journal of Agricultural and Food Chemistry.53 (5):1823–1827.doi:10.1021/jf048519s.PMID15740080.
