Ilex aquifolium (holly, common holly, English holly, European holly, or occasionally Christmas holly), is a species of holly native to western and southern Europe, northwest Africa, and southwest Asia. I. aquifolium is the species familiar in Christmas decoration, and is regarded as the type species of the genus Ilex, which by association is also called “holly”. It is a dioecious tree or shrub found, for example, in shady areas of forests of oak and in beech hedges. It has a great capacity to adapt to different conditions and is a pioneer species that repopulates the margins of forests or clearcuts.
As a tree, it can exceed 10 m in height. It is usually found as a shrub or a small tree about 1 m tall with a straight trunk and pyramidal crown, which branches from the base. It is slow growing and it does not usually fully mature due to grazing, cutting, or fire. It can live 500 years, but usually does not reach 100.
Edward Step had this to say about the Holly.
The Holly (Ilex aquifolium).
The Holly must be regarded as one of our small trees, although many specimens attain a height of forty or fifty feet, with a girth of ten or twelve feet. It is well distributed throughout our islands, ascending to a thousand feet, and it is probable that no other tree is so well known, by its foliage at least, as the Holly, or Holm, to give it its ancient name.
The word Holm was incorporated by some of our ancestors far back in the name Holmsdale, which still attaches to the stretch of country at the southern foot of the chalk hills in Surrey, and whose proud motto is, “Never wonne, ne never shall.” At the western end of the Holmsdale is Holmwood, and still a little further west Holmbury. In these places the Holly still grows bravely, not far from the old home of John Evelyn, who must be thought of whenever we talk of Hollies, though the recollection has to do with Sayes Court, his Thames-side house, where the barbarian Peter wrought such havoc with his cherished Holly-hedge. How Evelyn must have lamented that outrage is indicated in this extract from the “Sylva”:—
“Is there under heaven a more glorious and refreshing object of the kind, than an impregnable hedge of about four hundred feet in length, nine feet high, and five in diameter, which I can show in my now ruined gardens at Say’s Court (thanks to the Czar of Moscovy) at any time of the year, glittering with its armed and varnished leaves? The taller standards at orderly distance, blushing with their natural coral. It mocks the rudest assaults of the weather, beasts, or hedge-breakers, et illum nemo impunè lacessit.”
The bark of the Holly is smooth and pale-grey in colour. Time out of mind it has been used in the preparation of a viscid substance known as birdlime, which, spread on twigs, holds the feet of small birds. Respecting the foliage of the Holly, there is little need to say anything, but for uniformity’s sake we may note that the leaves are oval in shape, of a leathery consistence, with a firmer margin, running out into long sharp spines. It is a fact worthy of note that when the Holly has attained to a height of ten feet or so, it frequently clothes its upper branches in leaves that have no spines—a circumstance that Robert Southey sought to explain in his poem “The Holly-tree,” on teleological grounds. His second verse, however, contains sufficient explanation of the fact it describes:—
In some places the young shoots are gathered by the peasants, dried, bruised, and used as a winter cattle-food. No doubt, in the early history of the Holly, cattle found out its good qualities for themselves, and browsed upon the then-unarmed foliage. In self-defence the tree developed spines upon its leaves, and so kept its enemies at a respectful distance. Above the reach of these marauders the production of spines would be a useless waste of material.
Flowers of Holly.
The flowers of the Holly, though small, are conspicuous by their great number and white colour. They are about a quarter of an inch across, with four petals and four stamens or stigmas. Sometimes flowers with stamens are produced by the same tree that bears flowers with stigmas; but often the male and the female flowers are borne by separate trees, so that the possessor of a Holly that is solely male is sometimes puzzled by the fact that his tree, though covered with blossom, never produces a berry. The fruit is analogous in structure to that of the Plum and Cherry, and is technically termed a drupe; but instead of the single stone of these fruits, in the Holly-berry there are four bony little stones, each with its contained seed. The berries ripen about September, and are then scarlet and glossy, though here and there one finds a tree whose fruit never gets beyond the yellow stage of coloration.
Fruits of Holly.
Bole of Holly.
Most parts of the tree have had their uses in medicine; the leaves, for example, being said to have value as a febrifuge, and the berries as a purgative, or in large doses (6 to 8) as an emetic. The smooth bark of large Hollies is often attacked by one of the most striking of our native lichens—Graphis elegans—whose black fruiting portions look like a raised cuneiform inscription. The Holly is not greatly subject to the attacks of insects, but many of its leaves will be found to have been tunnelled between the upper and lower skins by the larva of a minute moth, one of the Leaf-miners. It also provides the pabulum for the caterpillar of the Holly-blue butterfly (Lycæna argiolus). The dead leaves may be examined for the minute Prickly Snail (Helix aculeata).
The wood of the Holly has an exceedingly fine grain, due to its slow growth, and it is very hard and white. These qualities make it valuable for many purposes, often as a substitute for Box-wood, and, when dyed black, in lieu of Ebony.
Holly is also listed in flowering trees and shrubs under the name Ilex and classed as a hardy ornamental suitable for London.
A D Webster the horticulturalist describes the Holly as follows:
ILEX AQUIFOLIUM.—Common Holly. Europe (Britain) and West Asia. Though the Hollies are not usually reckoned ornamental for the sake of their flowers, their berries are highly so. Some of them are nevertheless deliciously fragrant when in bloom. The leaves of this, our native species, in their typical form are oblong-ovate, wavy, and deeply spiny-toothed. The tree flowers in May and June, while the clusters of bright red berries ripen in autumn, persist all the winter, and sometimes even hang on tree till a second crop is matured, provided they are not devoured by birds during severe weather. The varieties are very numerous, and differ chiefly in the form and toothing of the leaves, which are variegated in many cases, their size and form, and in the colour of the berries in a few instances.
I. Aquifolium albo-marginata has ovate, nearly flat, spiny-serrate leaves, with a narrow silvery margin, and fruits freely. I. Aquifolium fructu albo has white berries; in I. Aquifolium fructu luteo they are yellow and very abundantly produced; and in I. Aquifolium fructu nigro they are black. I. Aquifolium handsworthensis has elliptic-oblong spiny leaves, with a creamy-white margin and marbled with gray. Grafted trees bear berries in great profusion from the time they are only a foot high, and are highly ornamental. I. Aquifolium Hodginsii has large, broadly oblong-ovate, slightly spiny leaves, and large crimson-red berries that ripen late in autumn. I. Aquifolium Hodginsii aurea is a sub-variety with a broad golden margin to the leaves, and the disc splashed with gray. Beautiful and distinct is I. Aquifolium Lawsoniana, with ovate, flat, almost spineless leaves, heavily and irregularly blotched with yellow in the centre. The berries are of a brilliant red. The variety differs from Milkmaid in having flat, nearly entire leaves. I. Aquifolium pendula has a wide, rounded, drooping head, but otherwise does not differ from the type. Many others bear berries, but the above are all very distinct forms.
I. OPACA.—American Holly. United States, 1744. The leaves of this species are oblong or oval, small, spiny-serrate, and of a dark opaque green. The berries, which ripen in autumn, are small, bright red, and very liable to be eaten by birds. In America this Holly is put to precisely the same purposes as the common Holly is in Europe. It is perfectly hardy here.
If left to its own devices, some ancient Holly can reach a height of 22m and live for over 300 years
— The Tree Council (@TheTreeCouncil) November 3, 2015