Reaching 14m in height, the common holly (Ilex aquifolium) is one of 400 species belonging to the Aquifoliaceae (holly family). The genus occurs throughout temperate, tropical and sub-tropical zones, and contains climbers, epiphytes, shrubs and trees. The leaves of most members of the genus are alternate, and are usually thick and leathery, with a crenate or entire leaf, which is often spined. The most familiar species is I. aquifolium which is a native of Europe, including the British Isles. It is often seen as a hedgerow species, where it provides shelter, and serves as a valuable food source for birds, bees, butterflies and moths. I. aquifolium has long been grown as a garden plant, and has given rise to a range of attractive cultivars, including ‘Argentea Marginata’, whose glossy foliage is edged with a silver margin, in striking contrast to the clusters of brilliant red berries.