Of all the trees that are in the wood, the holly wears the crown! There are four hundred or so evergreen and deciduous trees and shrubs that make up this large genus, which is Aquifoliaceae. Generally, species under this genus are known as holly. They come predominantly from the temperate regions of the northern hemisphere. They are grown for their foliage and produce clusters of small glossy berries. With its shiny green and spiky foliage as well as red berries, the holly tree in the snow looks like a Christmas tree decorated with red balls. Hollies make excellent hedges, border plants, tub plants, or screens for privacy according to their height. Celebrants put up holly for the Jul feast, which they believe holly will bring luck to the house in Scandinavia. In England, holly is a famous Christmas decoration that often used for Christmas cards and wrapping paper.
Trees of this genus are dioecious in which the male and female plants must be grown together to obtain the berries through cross-pollination. During the flowering period, the trees produce small and insignificant size of flowers that are greenish-white in colors. Then, the fruits are set, which are the berries that are red, yellow, or black in colors in summer, fall (autumn), or winter. Hollies grow well in deep, friable, well-drained soils with high organic content. They are full to frost hardy marginally. However, in cool climates, an open and sunny position is the best condition for it to thrive. Watering is needed throughout the hot and dry summers. Pruning is needed that can be conducted in spring to check the vigorous growth as hollies do not like transplanting. Vegetative propagation can be done through cuttings, whereas it also can be propagated through the seeds. The horticultural practice is needed to make sure there is no sign of holly aphid and holly leaf miner.
There are several popular species under this genus. A common species, English holly (Ilex aquifolium) is native to Europe, North Africa, and western Asia. It is an evergreen species that is a popular Christmas decoration in the northern hemisphere. It grows glossy, spiny-edged dark green leaves, and bright red winter berries. The tree itself can grow up to forty feet with a canopy of about fifteen feet or more as it has erect and branching stems for the spread. For this species, the most commonly grown cultivars are ‘Amber’ that has lovely yellow fruit and almost thornless; ‘Angustifolia’ green or purple twigs and lanceolate dark green foliage with a neat pyramidal shape; ‘Aurea Marginata’ is a small, bushy, silver holly with yellow margins on its spiny foliage that produce red berries. Other common cultivars are ‘Ferox Argentea’, ‘Golden Queen’, ‘Handsworth New Silver’, ‘J. C. van Tol’, ‘Madame Briot’, ‘Pyramidalis’, ‘Pyramidalis Fructu Luteo’, ‘Silver Milkmaid’, and ‘Silver Queen’.
Ilex x altaclerensis, which is known as Highclere holly, is a group of evergreen hybrid hollies that can reach up to fifty feet in height. It has larger and variable leaves and flowers as well as berries as compared to English holly. This hybrid has many cultivars such as ‘Belgica Aurea’ or ‘Silver Sentinel’ that has an upright female with few spined leaves that have a gray-green center with an irregular yellow margin. Moreover, the cultivar ‘Camelliifolia’ is a female plant with purple-tinged shoots, leaves, stems, and petal bases. It bears larger berries and long leaves with only a few spines. Ilex x altaclerensis ‘Golden King’ is a frost-hardy female with smooth-edged, deep, and dark green leaves with yellow margins that makes it an excellent hedge. ‘Hendersonii’ is a cultivar that has a compact female flower with dull green foliage that bear long-lasting berries. ‘Hodginsii’, ‘Lawsoniana’, and ‘Wilsonii’ are other cultivars of this hybrid.
Moreover, two popular species are found in China. Ilex pernyi that commonly known as Perny’s holly, is found in central and western China. It is a densely branched evergreen tree that was named after the French missionary Paul Perny. It has distinctive, diamond-shaped, and triangular-spined leaves that bear oval red berries. This species does not tolerate dry conditions but is very frosty. There is a hybrid of I. cross-pollination and I. pernyi, which known as Ilex x aquipernyi. Chinese holly that scientifically known as Ilex cornuta is a self-fertile species that is better suited than other species to mild-winter climates. It is a fully frost-hardy, dense, and rounded shrub from China. The thick glossy leaves are almost rectangular with spiny points. The berries are larger and borne throughout the summer, but it is not as profuse as English Holly.
Besides, two species originated from Japan, which are Ilex crenata and I. serrata. I. crenata is referred to as Japanese holly as a frost-hardly, compact evergreen shrub, which has stiff branches that possess small, scalloped leaves, full white flowers, and glossy black color berries. In Japan, it is often used for clipped hedges and topiary. It is usually trimmed into smaller sizes in cultivation. It has variegated or pale-leafed forms that do best in full sun, whereas the green-leafed forms do well in partial shade. Then, I. serrata is called Japanese winterberry or fine-tooth holly that has spreading branches with egg-shaped leaves, pale pink flowers, as well as an abundance of tiny red berries.
Furthermore, several species are found in the USA. The best-known American species is I. opaca (American holly) has an erect habit and produces red berries in winter. It prefers a sunny position and acid soil and does not do well near the sea. Ilex decidua is found in the southeastern USA as a frost-hardy shrub or small tree that grows to ten feet, but it can become a tree that reaches up to thirty feet. It is commonly called possum haw as a deciduous with bright orange or red berries that last into winter. Ilex verticillate that usually referred to as winterberry, black alder, or coralberry. It is originated from the eastern USA as a deciduous shrub with purple-tinged toothed leaves in spring and turn yellow in autumn. It has few cultivars under this species, which are ‘Cacapon’, ‘Nana’, and ‘Winter Red’.
Yaupon holly that scientifically known as I. vomitoria is found in the southeastern USA and Mexico as a quick-growing species that makes a good hedge or screen. It is also known as Carolina tea as native Americans used its leaves that contain an emetic substance to prepare a purgative drink. Another species that can be used as tea is I. paraguariensis that has common names like maté, yerba maté, and Paraguay tea. People native to South America used the dried leaves to make maté, which is a drink that is rich in caffeine. Moreover, a species called Ilex mitis (cape holly) is native to southern and eastern African that has a spreading dense crown with small white flowers in spring followed by red berries in early summer.
Rätsch. C. & Műller-Ebeling. C. (2009). Pagan Christmas – The plant, spirits, and rituals at the origins of Yuletide. Rochester, Vermont.