Holly Temporal range: | |
---|---|
European holly ( Ilex aquifolium ) leaves and fruit | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Asterids |
Order: | Aquifoliales |
Family: | Aquifoliaceae DC. ex A.Rich. |
Genus: | Ilex L. |
Type species | |
Ilex aquifolium | |
Species | |
About 570, see text |
Ilex ( /ˈaɪlɛks/ ) or holly [3] is a genus of over 570 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. [4] Ilex has the most species of any woody dioecious angiosperm genus. [5] The species are evergreen or deciduous trees, shrubs, and climbers from tropics to temperate zones worldwide. The type species is Ilex aquifolium , the common European holly used in Christmas decorations and cards.
The genus Ilex is divided into three subgenera: [6]
The genus is widespread throughout the temperate and subtropical regions of the world. It includes species of trees, shrubs, and climbers, with evergreen or deciduous foliage and inconspicuous flowers. Its range was more extended in the Tertiary period and many species are adapted to laurel forest habitats. It occurs from sea level to more than 2,000 m (6,600 ft) with high mountain species. It is a genus of small, evergreen trees with smooth, glabrous, or pubescent branchlets. The plants are generally slow-growing with some species growing to 25 m (82 ft) tall. The type species is the European holly Ilex aquifolium described by Linnaeus. [2] Plants in this genus have simple, alternate glossy leaves, frequently with a spiny leaf margin. The inconspicuous flower is greenish white, with four petals. They are generally dioecious, with male and female flowers on different plants. [7]
The small fruits of Ilex, although often referred to as berries, are technically drupes. [8] They range in color from red to brown to black, and rarely green or yellow. The "bones" contain up to ten seeds each. Some species produce fruits parthenogenetically, such as the cultivar 'Nellie R. Stevens'. The fruits ripen in winter and thus provide winter colour contrast between the bright red of the fruits and the glossy green evergreen leaves. Hence the cut branches, especially of I. aquifolium, are widely used in Christmas decoration. The fruits are generally slightly toxic to humans, and can cause vomiting and diarrhea when ingested. However, they are a food source for certain birds and other animals, which help disperse the seeds. Unfortunately this can have negative impacts as well. Along the west coast of North America, from California to British Columbia, English holly (Ilex aquifolium), which is grown commercially, is quickly spreading into native forest habitat, where it thrives in shade and crowds out native species. It has been placed on the Washington State Noxious Weed Control Board's monitor list, and is a Class C invasive plant in Portland. [9] [10] [11] [12]
Ilex in Latin means the holm-oak or evergreen oak ( Quercus ilex ). Despite the Linnaean classification of Ilex as holly, as late as the 19th century in Britain, the term Ilex was still being applied to the oak as well as the holly – possibly due to the superficial similarity of the leaves. [13] [14] The name "holly" in common speech refers to Ilex aquifolium , specifically stems with berries used in Christmas decoration. By extension, "holly" is also applied to the whole genus. The origin of the word "holly" is considered a reduced form of Old English hole(ġ)n, [15] Middle English Holin, later Hollen. [16] [17] The French word for holly, houx, derives from the Old Low Franconian *hulis (Middle Dutch huls). [18] Both are related to Old High German hulis, huls, [19] as are Low German/Low Franconian terms like Hülse or hulst. These Germanic words appear to be related to words for holly in Celtic languages, such as Welsh celyn, Breton kelen(n) and Irish cuileann. [20]
Several Romance languages use the Latin word acrifolium, literally "sharp leaf" (turned into aquifolium in modern time), hence Italian agrifoglio, Occitan grefuèlh, etc. [21]
The phylogeography of this group provides examples of various speciation mechanisms at work. In this scenario ancestors of this group became isolated from the remaining Ilex when the Earth mass broke away into Gondwana and Laurasia about 82 million years ago, resulting in a physical separation of the groups and beginning a process of change to adapt to new conditions. This mechanism is called allopatric speciation. Over time, survivor species of the holly genus adapted to different ecological niches. This led to reproductive isolation, an example of ecological speciation. In the Pliocene, around five million years ago, mountain formation diversified the landscape and provided new opportunities for speciation within the genus.
The fossil record indicates that the Ilex lineage was already widespread prior to the end of the Cretaceous period; the earliest records of the distinctive pollen of Ilex are from the Turonian of the Otway Basin of Australia. The earliest fossil holly fruit is known from the Maastrichtian of central Europe. [22] Based on the molecular clock, the common ancestor of most of the extant species probably appeared during the Eocene, about 50 million years ago, suggesting that older representatives of the genus belong to now extinct branches. [23] Ilex sinica seems to be the most basal extant species. [24] The laurel forest covered great areas of the Earth during the Paleogene, when the genus was more prosperous. This type of forest extended during the Neogene, more than 20 million years ago. Most of the last remaining temperate broadleaf evergreen forests are believed to have disappeared about 10,000 years ago at the end of the Pleistocene. Many of the then-existing species with the strictest ecological requirements became extinct because they could not cross the barriers imposed by the geography, but others found refuge as a species relict in coastal enclaves, archipelagos, and coastal mountains sufficiently far from areas of extreme cold and aridity and protected by the oceanic influence.
The genus is distributed throughout the world's different climates. Most species make their home in the tropics and subtropics, with a worldwide distribution in temperate zones. The greatest diversity of species is found in the Americas and in Southeast Asia.
Ilex mucronata , formerly the type species of Nemopanthus , is native to eastern North America. [25] Nemopanthus was treated as a separate genus with eight species. [26] of the family Aquifoliaceae, now transferred to Ilex on molecular data; [27] it is closely related to Ilex amelanchier . [28]
In Europe the genus is represented by a single species, the classically named holly Ilex aquifolium , and in continental Africa by this species and Ilex mitis . Ilex canariensis , from Macaronesia, and Ilex aquifolium arose from a common ancestor in the laurel forests of the Mediterranean. Australia, isolated at an early period, has Ilex arnhemensis . Of 204 species growing in China, 149 species are endemic. A species which stands out for its economic importance in Spanish-speaking countries and in Brazil is Ilex paraguariensis or Yerba mate. Having evolved numerous species that are endemic to islands and small mountain ranges, and being highly useful plants, many hollies are now becoming rare.
Often the tropical species are especially threatened by habitat destruction and overexploitation. At least two species of Ilex have become extinct recently, and many others are barely surviving. [29]
They are an extremely important food for numerous species of birds, and also are eaten by other wild animals. In the autumn and early winter the fruits are hard and apparently unpalatable. After being frozen or frosted several times, the fruits soften, and become milder in taste. During winter storms, birds often take refuge in hollies, which provide shelter, protection from predators (by the spiny leaves), and food. The flowers are sometimes eaten by the larva of the double-striped pug moth (Gymnoscelis rufifasciata). Other Lepidoptera whose larvae feed on holly include Bucculatrix ilecella , which feeds exclusively on hollies, and the engrailed (Ectropis crepuscularia).
Holly can contain caffeic acid, caffeoyl derivatives, caffeoylshikimic acid, chlorogenic acid, feruloylquinic acid, quercetin, quinic acid, kaempferol, tannins, rutin, caffeine, theobromine, and ilicin. [30] [31]
Holly berries can cause vomiting and diarrhea. They are especially dangerous in cases involving accidental consumption by children attracted to the bright red berries. [32] Ingestion of over 20 berries may be fatal to children. [31] [32]
Holly leaves, if eaten, might cause diarrhea, nausea, vomiting, and stomach and intestinal problems. [32]
Holly plants might be toxic to pets and livestock. [33]
Leaves of some holly species are used by some cultures to make daily tea. These species are Yerba mate (I. paraguariensis), Ilex guayusa , Kuding ( Ilex kaushue ), Yaupon (I. vomitoria) and others. Leaves of other species, such as gallberry (I. glabra) are bitter and emetic. [34] In general little is known about inter-species variation in constituents or toxicity of hollies.
Holly berries are fermented and distilled to produce an eau de vie . [35] [36]
Many of the holly species are widely used as ornamental plants in temperate/European gardens and parks, notably:
Hollies are often used for hedges; the spiny leaves make them difficult to penetrate, and they take well to pruning and shaping. [38] Many hundreds of hybrids and cultivars have been developed for garden use, among them the very popular "Highclere holly", Ilex × altaclerensis (I. aquifolium × I. perado) and the "blue holly", Ilex × meserveae (I. aquifolium × I. rugosa ). [39] The cultivars I. × meserveaeBlue Prince = 'Conablu' and Blue Princess = 'Conapri' [40] have gained the Royal Horticultural Society's Award of Garden Merit. [41] [42] Another hybrid is Ilex × koehneana, with the cultivar 'Chestnut Leaf'. [43]
Holly – more specifically the European holly, Ilex aquifolium – is commonly referenced at Christmas time, and is often referred to by the name Christ's thorn. [44] [45] In many Western Christian cultures, holly is a traditional Christmas decoration, [46] used especially in wreaths and illustrations, for instance on Christmas cards. Since medieval times the plant has carried a Christian symbolism, [47] as expressed in the traditional Christmas carol "The Holly and the Ivy", in which the holly represents Jesus and the ivy represents the Virgin Mary. [45] Angie Mostellar discusses the Christian use of holly at Christmas, stating that: [45]
Christians have identified a wealth of symbolism in its form. The sharpness of the leaves help to recall the crown of thorns worn by Jesus; the red berries serve as a reminder of the drops of blood that were shed for salvation; and the shape of the leaves, which resemble flames, can serve to reveal God's burning love for His people. Combined with the fact that holly maintains its bright colors during the Christmas season, it naturally came to be associated with the Christian holiday. [45]
In heraldry, holly is used to symbolize truth. The Norwegian municipality of Stord has a yellow twig of holly in its Coat-of-arms.[ citation needed ]
The Druids held that "leaves of holly offered protection against evil spirits" and thus "wore holly in their hair". [45]
In the Harry Potter novels, holly is used as the wood in Harry's wand. [48]
In some traditions of Wicca, the Holly King is one of the faces of the Sun God. He is born at midsummer and rules from Mabon to Ostara.[ citation needed ]
In the Irish language, the words mac cuilinn mean 'son of holly'. Common anglicized forms of this arose; last names such as McCullen, McCullion, McQuillan, and MacCullion, which are quite common surnames in some areas.[ citation needed ]
Yerba mate or yerba-maté is a plant species of the holly genus Ilex native to South America. It was named by the French botanist Augustin Saint-Hilaire. The leaves of the plant can be steeped in hot water to make a beverage known as mate. Brewed cold, it is used to make tereré. Both the plant and the beverage contain caffeine.
Berberis aquifolium, the Oregon grape or holly-leaved barberry, is a species of flowering plant in the family Berberidaceae, native to western North America. It is an evergreen shrub growing 1–3 meters tall and 1.5 m (5 ft) wide, with pinnate leaves consisting of spiny leaflets, and dense clusters of yellow flowers in early spring, followed by dark bluish-black berries.
Ilex opaca, the American holly, is a species of holly, native to the eastern and south-central United States, from coastal Massachusetts south to central Florida, and west to southeastern Missouri and eastern Texas.
Mahonia is a formerly accepted genus of approximately 70 species of shrubs or, rarely, small trees with evergreen leaves in the family Berberidaceae, native to eastern Asia, the Himalaya, North America, and Central America. They are closely related to the genus Berberis and as of 2023 the majority of botanical sources list it as a synonym for Berberis.
Ilex vomitoria, commonly known as yaupon or yaupon holly, is a species of holly that is native to southeastern North America. The word yaupon was derived from the Catawban yą́pą, from yą- tree + pą leaf. Another common name, cassina, was borrowed from Timucua. The Latin name comes from an observation by early Europeans that the ingestion of the plant was followed by vomiting in certain ceremonies.
Ilex verticillata, the winterberry, is a species of holly native to eastern North America in the United States and southeast Canada, from Newfoundland west to Ontario and Minnesota, and south to Alabama.
Ilex aquifolium, the holly, common holly, English holly, European holly, or occasionally Christmas holly, is a species of flowering plant in the family Aquifoliaceae, native to western and southern Europe, northwest Africa, and southwest Asia. It is regarded as the type species of the genus Ilex, which by association is also called "holly". It is an evergreen tree or shrub found, for example, in shady areas of forests of oak and in beech hedges. In the British Isles it is one of very few native hardwood evergreen trees. It has a great capacity to adapt to different conditions and is a pioneer species that repopulates the margins of forests or clearcuts.
Ilex mucronata, the mountain holly or catberry, is a species of holly native to eastern North America, from Newfoundland west to Minnesota, and south to Maryland and West Virginia.
Ilex guayusa is a species of tree of the holly genus, native to the Amazon Rainforest. One of four known caffeinated holly trees, the leaves of the guayusa tree are harvested fresh and brewed like a tea for their stimulative effects. It is known simply as guayusa in western languages like Spanish, as waisa in Kichwa and as wayus or wais in Shuar.
Kuding is a particularly bitter-tasting Chinese infusion, which due to their similarities in appearance is derived from several plant species. The two most common plants used to make kuding are the wax tree species Ligustrum robustum and the holly species Ilex kaushue, the former being more commonly grown in Sichuan and Japan while the latter is most commonly grown and used in the rest of China. Tea produced from Ligustrum or many species of Ilex is caffeine-free, although not Ilex paraguariensis, the source of mate drank in South America.
Ilex glabra, also known as Appalachian tea, evergreen winterberry, Canadian winterberry, gallberry, inkberry, dye-leaves and houx galbre, is a species of evergreen holly native to the coastal plain of eastern North America, from coastal Nova Scotia to Florida and west to Louisiana where it is most commonly found in sandy woods and peripheries of swamps and bogs. Ilex glabra is often found in landscapes of the middle and lower East Coast of the United States. It typically matures to 5–8 ft (1.5–2.4 m) tall, and can spread by root suckers to form colonies. It normally is cultivated as an evergreen shrub in USDA zones 6 to 10.
Ilex decidua is a species of holly native to the United States.
Osmanthus heterophyllus, variously known as holly osmanthus, holly olive, and false holly, is a species of flowering plant in the olive family Oleaceae, native to eastern Asia in central and southern Japan and Taiwan.
Ilex canariensis, the small-leaved holly, is an endemic species of holly native to Macaronesian islands. It is a species of plant in the family Aquifoliaceae. It is found in the Macaronesian islands of Madeira (Portugal) and Canary Islands (Spain).
Christmas plants are flowers or vegetation from garden plants associated with the festive season of Christmas. There are also a wide variety of plants that include "Christmas" in their common name.
Ilex cornuta, commonly known as Chinese holly or horned holly, is a slow-growing, densely foliaged evergreen shrub in the Aquifoliaceae plant family. It is native to eastern China and Korea and attains a height of about 3 metres (9.8 ft). The leaves are usually 5-spined, between 3.5 cm and 10 cm long, oblong and entire. The fruits are red berries, which are larger than those of the European Holly.
Ilex rotunda, commonly called the Kurogane holly, is an evergreen tree in the holly family (Aquifoliaceae). It is native to east Asia, where it is found in China, Japan, Korea, Taiwan, and Vietnam. Its natural habitat is in evergreen broadleaf forests, often in sunny areas such forest edges or on mountain slopes.
Ilex pernyi is a species in the Ilex (holly) genus and the family Aquifoliaceae. This evergreen shrub or small tree occurs in Mongolia and the south-west of China, specifically in Anhui, Gansu, and Shaanxi. The leaves are diamond-shaped with sharply toothed margins, opposite on the many branches. The small flowers are yellow, and berries on the female plants are red.
Ilex serrata is a species in the Ilex (holly) genus and the family Aquifoliaceae. It is an evergreen shrub or small tree up to about 4.5 m high. In Japan where it naturally occurs, it is a hardy species with ovate dark green leaves, pink flowers and red berries on the female plant.
Ilex umbellulata is an evergreen tree species related to holly, generally four to fifteen metres in height. It is found in Southeast Asia. This tree is most often found growing in forests.
In Germany and Scandinavia the holly, or holy tree, is called "Christ's thorn," from its use in church decorations, and because it bears berries at Christmas-tide.
Holly is still a popular Christmas decoration among Christian cultures.
The British native holly (Ilex aquifolim) has tremendous religious significance at Christmas. Its prickly leave are evocative of the crown of thorns that was placed on Jesus Christ's head at His crucifixion, and its scarlet berries are synonymous with drops of His blood.