You may have never realized this, but there are actually over six hundred types of holly trees and shrubs. Holly, whose botanical name is Ilex, is a flowering plant that produces berries that are toxic to human beings. Holly trees are evergreens, which makes them very popular with gardeners who live in cold climates. Holly is also very popular with Americans as a Christmas decoration, particularly because some types have dark green leaves and bright red berries. Holly is even used to make a tea called Yerba Mate in South America and the leaves of the guayusa species of holly have the highest caffeine content of any leaf known to man.
English holly trees are grown as ornamental specimens by gardeners around the world. These holly trees can grow into large, pyramid shapes and their very dense foliage makes them a good choice for decorative pruning. It is very easy to trim these holly trees into globes or even cubes. These hollies also have very bright red fruit and some of them have pretty, multi colored leaves. The 'Rubricaulis Aurea' type has forest green leaves with cream colored stripes and the 'Peter's' type has dark red berries and suffers little damage though even the coldest of winters.
The altaciere holly tree will grow larger than any other type of holly. This holly has been known to grow into a pyramid over 30 feet tall when mature. This holly tree bears shiny, dark green leaves and big, bright, red fruits. It is very hardy throughout the winter and requires little maintenance once established.
American holly trees come in many hybrids and were bred to withstand cold weather. Some trees, like the 'Old Heavy Berry' were bred to produce an abundance of bright red fruits during the winter time. Others, like the 'John Wister' have dark, blackish green foliage that grows very quickly.