There are approximately 400 species of holly found in all regions of the world with the exception of the Arctic and Antarctic.
Most holly species are trees or shrubs but some are climbers and others grow as epiphytes - plants which grow perched on other trees.
There are deciduous species as well as evergreens.
The leaves of several species contain caffeine and are used to make a stimulating tea. The best know is yerba maté, made from the leaves of Ilex paraguayensis.
Ilex aquifolium is native to western and central Europe from Norway, Denmark and the UK, and south as far as the Mediterranean region, where it occurs mainly in cooler mountain areas.