There are 12 varieties of holly trees, with the most common being American holly, English holly, Carolina holly, Chinese holly and common winterberry holly. Less common varieties include finetooth holly, Hawaiian holly, inkberry holly, Japanese holly, lusterleaf holly, myrtle-leaved holly and yaupon holly.
Most varieties of holly trees have leaves with serrated edges or spiny teeth. Many varieties are also dioecious, which means they require female and male plants to produce fruit. A single male holly plant can pollinate multiple female plants. The females then produce a seed called a drupe. They look like berries and come in various colors, such as red, purple, black, white and yellow.