Holly

Ilex , or holly, is a  genus of about 480 species of flowering plants in the family Aquifoliaceae, and the only living genus in that family. The species are evergreen or deciduous trees, shrubs, and climbers from tropics to temperate zones worldwide.

Description

The genus Ilex includes about 480 species,  divided into three subgenera:
 Ilex subg. Byronia, with the type species Ilex polypyrena
 Ilex subg. Prinos, with 12 species
 Ilex subg. Ilex, with the rest of the species

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  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  tall. The type species is the European holly Ilex aquifolium described by Linnaeus.

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.

The small fruits of Ilex, although often referred to as berries, are technically drupes. 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 an important food source for 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.

Etymology
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.  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 , Middle English Holin, later Hollen.

The French word for holly, , derives from the Old Low Franconian *hulis (Middle Dutch huls). Both are related to Old High German , huls, as are Low German/Low Franconian terms like  or . These Germanic words appear to be related to words for holly in Celtic languages, such as Welsh , Breton  and Irish .

Several Romance languages use the Latin word acrifolium, literally "sharp leaf" (turned into aquifolium in modern time), so Italian , Occitan , etc.

History

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 82million 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. Based on the molecular clock, the common ancestor of most of the extant species probably appeared during the Eocene, about 50million years ago, suggesting that older representatives of the genus belong to now extinct branches. 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 20million 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.

Range
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. Nemopanthus was treated as a separate genus with eight species. of the family Aquifoliaceae, now transferred to Ilex on molecular data; it is closely related to Ilex amelanchier.

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.

Ecology
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.

They are 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).

Toxicity
Holly can contain caffeic acid, caffeoyl derivatives, caffeoylshikimic acid, chlorogenic acid, feruloylquinic acid, quercetin, quinic acid, kaempferol, tannins, rutin,  caffeine, and theobromine.

Holly berries can cause vomiting and diarrhea.  They are especially dangerous in cases involving accidental consumption by children attracted to the bright red berries.   Ingestion of over 20 berries may be fatal to children.

Holly leaves, if eaten, might cause diarrhea, nausea, vomiting, and stomach and intestinal problems.

Holly plants might be toxic to pets and livestock.

Uses

Culinary use
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.  In general little is known about inter-species variation in constituents or toxicity of hollies.

Ornamental use
Many of the holly species are widely used as ornamental plants in temperate/European gardens and parks, notably:
 I. aquifolium (common European holly)
 I. crenata (box-leaved holly)
 I. verticillata (winterberry)
Moreover, 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). The cultivar I. × meserveae Blue Prince = ‘Conablu’ has gained the Royal Horticultural Society’s Award of Garden Merit.  Hollies are often used  for hedges; the spiny leaves make them difficult to penetrate, and they take well to pruning and shaping.

Culture

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. In many Western Christian cultures, holly is a traditional Christmas decoration, used especially in wreaths and illustrations, for instance on Christmas cards. Since medieval times the plant has carried a Christian symbolism, as expressed in the well-known Christian Christmas carol "The Holly and the Ivy", in which the holly represents Jesus and the ivy represents the Virgin Mary. Angie Mostellar discusses the Christian use of holly at Christmas, stating that:

In heraldry, holly is used to symbolize truth. The Norwegian municipality of Stord has a yellow twig of holly in its Coat-of-arms.

The Druids held that "leaves of holly offered protection against evil spirits" and thus "wore holly in their hair".

In the Harry Potter novels, holly is used as the wood in Harry's wand.

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.

Selected species

 Ilex abscondita (Venezuela)
 Ilex aculeolata
 Ilex acutidenticulata (Venezuela)
 Ilex affinis
 Ilex aggregata
 Ilex × altaclarensis
 Ilex altiplana (Venezuela)
 Ilex amazonensis –
 Ilex ambigua – Sand holly (southeastern and south-central United States)
 Ilex amboroica
 Ilex amelanchier (southeastern United States)
 Ilex amygdalina (South America)
 Ilex andicola (South America)
 Ilex angulata
 Ilex anodonta
 Ilex anomala Hook. & Arn. – Kāwau (Hawaii)
 Ilex anonoides (Peru)
 Ilex apicidens
 Ilex aquifolium – European holly, English holly, Christ's thorn (western and southern Europe, northwest Africa, and southwest Asia)
 Ilex aracamuniana (Venezuela)
 Ilex archeri
 Ilex ardisiifrons
 Ilex argentina
 Ilex arimensis
 Ilex arisanensis (Taiwan)
 Ilex arnhemensis (Western Australia, the Northern Territory and Queensland)
 Ilex asprella (southeast Asia)
 Ilex atabapoensis
 Ilex atrata
 Ilex auriculata
 Ilex austrosinensis
 Ilex belizensis
 Ilex berteroi
 Ilex bidens
 Ilex bioritsensis
 Ilex blanchetii
 Ilex boliviana
 Ilex brachyphylla (China)
 Ilex brandegeeana
 Ilex brasiliensis (Brazil, Paraguay and northern Argentina)
 Ilex brevicuspis
 Ilex brevipedicellata (Venezuela)
 Ilex buergeri
 Ilex buxoides
 Ilex canariensis (Macaronesian islands)
 Ilex caniensis (Peru)
 Ilex casiquiarensis
 Ilex cassine – Dahoon holly, cassena (Virginia to southeast Texas of US, Veracruz of Mexico, Bahamas, Cuba, and Puerto Rico)
 Ilex cauliflora
 Ilex centrochinensis
 Ilex cerasifolia (Brazil)
 Ilex chamaebuxus
 Ilex chamaedryfolia
 Ilex championii
 Ilex chapaensis (China)
 Ilex chartaceifolia
 Ilex chengbuensis
 Ilex chengkouensis (China)
 Ilex cheniana
 Ilex chinensis
 Ilex chingiana
 Ilex chiriquensis
 Ilex chuniana (China)
 Ilex ciliolata (Venezuela)
 Ilex ciliospinosa
 Ilex cinerea
 Ilex clementis
 Ilex cochinchinensis
 Ilex colchica (Bulgaria, Turkey and the Caucasus)
 Ilex collina (North Carolina, Virginia, West Virginia, Tennessee, and Georgia of the United States)
 Ilex colombiana
 Ilex condensata
 Ilex confertiflora
 Ilex conocarpa (Brazil)
 Ilex cookii (Puerto Rico)
 Ilex corallina
 Ilex coriacea – gallberry (Virginia to Texas of United States)
 Ilex cornuta – Chinese holly, horned holly (eastern China and Korea)
 Ilex costaricensis (Costa Rica, Nicaragua, and Panama)
 Ilex cowanii (Venezuela)
 Ilex crenata – Japanese holly, box-leaved holly, inutsuge (Japanese) (eastern China, Japan, Korea, Taiwan, and Sakhalin)
 Ilex cubana
 Ilex culmenicola
 Ilex cupreonitens
 Ilex curtissii
 Ilex cuzcoana
 Ilex cyrtura
 Ilex dabieshanensis (China)
 Ilex danielis
 Ilex daphnogenea
 Ilex dasyclada
 Ilex dasyphylla
 Ilex davidsei (Venezuela)
 Ilex decidua Walter – possumhaw (eastern United States, northeastern Mexico)
 Ilex dehongensis
 Ilex delavayi
 Ilex denticulata
 Ilex dianguiensis
 Ilex dicarpa
 Ilex dimorphophylla (Amami Ōshima of the Ryukyu Islands)
 Ilex dioica
 Ilex diospyroides (Venezuela)
 Ilex dipyrena – Himalayan holly
 Ilex dicolor
 Ilex diuretica
 Ilex divaricata
 Ilex dolichopoda
 Ilex dubia
 Ilex dugesii
 Ilex duidae
 Ilex dumosa
 Ilex dunniana
 Ilex editicostata
 Ilex elliptica
 Ilex elmerrilliana
 Ilex embelioides
 Ilex eoa
 Ilex ericoides (Peru)
 Ilex estriata
 Ilex euryoides (China)
 Ilex excelsa
 Ilex fargesii
 Ilex fengqingensis (China)
 Ilex ficifolia
 Ilex ficoidea
 Ilex florifera (Jamaica)
 Ilex formosana
 Ilex forrestii
 Ilex fragilis
 Ilex franchetiana
 Ilex fukeinensis
 Ilex gabinetensis
 Ilex gabrielleana
 Ilex gardneriana (extinct: 20th century?) (India)
 Ilex georgei
 Ilex gintungensis
 Ilex glabella (Venezuela)
 Ilex glabra L. A.Gray – evergreen winterberry, bitter gallberry, inkberry (eastern North America)
 Ilex glaucophylla
 Ilex gleasoniana (Venezuela)
 Ilex glomerata (Burma, Sumatra, Peninsular Malaysia and Borneo)
 Ilex godajam
 Ilex goshiensis
 Ilex graciliflora (China)
 Ilex gracilis
 Ilex grandiflora (Peninsular Malaysia)
 Ilex gransabanensis
 Ilex guaiquinimae (Venezuela)
 Ilex guangnanensis
 Ilex guayusa (Amazon rainforest)
 Ilex guianensis
 Ilex guizhouensis
 Ilex gundlachiana
 Ilex haberi
 Ilex hainanensis
 Ilex hanceana
 Ilex harrisii (Jamaica)
 Ilex hayatana
 Ilex hemiepiphytica (Costa Rica)
 Ilex hippocrateoides
 Ilex hirsuta
 Ilex holstii (Venezuela)
 Ilex hookeri
 Ilex huachamacariana (Venezuela)
 Ilex hualgayoca (South America)
 Ilex huana
 Ilex hylonoma
 Ilex hypaneura
 Ilex hyreana
 Ilex ignicola (Venezuela)
 Ilex illustris (Peninsular Malaysia)
 Ilex integerrima (Brazil)
 Ilex integra – mochi tree, Nepal holly (Korea; Taiwan; the mid-southern regions of China; and Honshu, Shikoku and Kyushu in Japan)
 Ilex intricata
 Ilex inundata (South America)
 Ilex jamaicana Proctor (Jamaica)
 Ilex jauaensis(Venezuela)
 Ilex jelskii (Peru)
 Ilex karuaiana (Venezuela)
 Ilex kaushue (China)
 Ilex khasiana (India)
 Ilex kingiana
 Ilex kusanoi
 Ilex laevigata – smooth winterberry (eastern coastal United States)
 Ilex lasseri (Venezuela)
 Ilex latifolia – tarajo holly, tarayō (Japanese) (southern Japan and eastern and southern China )
 Ilex lechleri (Peru)
 Ilex leucoclada
 Ilex longipes (southeastern United States)
 Ilex longzhouensis (China)
 Ilex machilifolia (southern China)
 Ilex maclurei (China)
 Ilex macoucoua
 Ilex macrocarpa
 Ilex macropoda
 Ilex magnifructa (Venezuele)
 Ilex maingayi (Malaysia)
 Ilex marahuacae (Venezuela)
 Ilex marginata (Venezuela)
 Ilex margratesavage
 Ilex mathewsii (Peru)
 Ilex × meserveae
 Ilex microdonta
 Ilex mitis (Southern Africa)
 Ilex montana Torrey & A.Gray – mountain winterberry (Eastern United States)
 Ilex mucronata (L.) M.Powell, Savol., & S.Andrews – mountain holly, catberry (Eastern North America)
 Ilex myrtifolia – myrtle holly, myrtle dahoon
 Ilex neblinensis (Brazil, Venezuela)
 Ilex nothofagifolia
 Ilex oblonga (China)
 Ilex occulta (China)
 Ilex opaca – American holly (Eastern United States)
 Ilex ovalifolia
 Ilex palawanica (Philippines)
 Ilex pallida (Costa Rica, Nicaragua, and Panama)
 Ilex paraguariensis – yerba mate (mate, erva-mate)
 Ilex parvifructa (Venezuela)
 Ilex patens
 Ilex pauciflora
 Ilex paujiensis
 Ilex pedunculosa – longstalked holly
 Ilex peiradena
 Ilex perado – Madeiran holly
 Ilex perlata
 Ilex pernyi – Perny's holly
 Ilex polita
 Ilex praetermissa
 Ilex pringlei
 Ilex pseudobuxus
 Ilex puberula
 Ilex pubescens
 Ilex purpurea
 Ilex qianlingshanensis
 Ilex quercetorum
 Ilex quercifolia
 Ilex rarasanensis
 Ilex reticulata
 Ilex rotunda
 Ilex rugosa
 Ilex sclerophylla
 Ilex serrata – Japanese winterberry
 Ilex sessilifructa
 Ilex shimeica
 Ilex sikkimensis
 Ilex sintenisii (Urban) Britt. – Sintenis' holly (Puerto Rico)
 Ilex sipapoana
 Ilex socorroensis
 Ilex spinigera or Ilex hyrcana Pojark. 
 Ilex spruceana
 Ilex steyermarkii
 Ilex subrotundifolia
 Ilex subtriflora
 Ilex sugerokii
 Ilex sulcata
 Ilex syzygiophylla
 Ilex tahanensis
 Ilex tarapotina
 Ilex tateana
 Ilex taubertiana
 Ilex ternatiflora (extinct: 20th century?)
 Ilex theezans
 Ilex tiricae
 Ilex tolucana
 Ilex trachyphylla
 Ilex trichocarpa
 Ilex tugitakayamensis
 Ilex uraiensis
 Ilex urbaniana – Urban's holly
 Ilex vaccinoides
 Ilex venezuelensis
 Ilex venulosa
 Ilex verticillata (L.) A.Gray American winterberry (Eastern North America)
 Ilex vomitoria – yaupon holly (southeastern United States)
 Ilex vulcanicola
 Ilex walkeri
 Ilex wenchowensis
 Ilex williamsii
 Ilex wilsonii
 Ilex yunnanensis
 Ilex wugonshanensis
 Ilex yuiana

Gallery

References

External links
 
 Aquifoliaceae in BoDD – Botanical Dermatology Database

 
Category:Medicinal plants
Category:Winter traditions
Category:Christmas plants
Category:Dioecious plants
Category:Poisonous plants
Category:Flora of North America
Category:Flora of East Asia
Category:Flora of Asia