Holly, common name for shrub of the holly family Aquifoliaceae. The true hollies belong to genus Ilex, comprising some 400 species worldwide, mostly in Central and South America. Two species occur in Canada. Although well-known for their spiny leaves and red berries, many hollies are nonspiny with black berries. Inkberry (I. glabra) has black berries and shiny, evergreen leaves; black alder (I. verticillata) has bright red berries and dull green, deciduous leaves. The closely related mountain holly (Nemopanthus mucronata) is deciduous and red-berried.

All 3 inhabit wet woods and swamps in eastern Canada. Numerous cultivars exist, selected for their ornamental qualities (eg, leaf variegation) and their compact growth. The name "holly" (from holy) suggests its long association with folklore and religion. The druid ritual of bringing sprigs of the plant indoors to provide winter refuge for woodland spirits continues today at Christmastime. The hard, white wood is used by cabinetmakers. Various parts of the holly plant were used to make a tonic in Europe and North America, and species like I. paraguariensis (yerba maté) provide a caffeine tea in Central and South America and Asia.