Holly and mistletoe are symbols of the Christmas season. They are very different plants, but both quite beautiful in their own unique ways.
Mistletoe is actually quite a pest in the South. It is most often found in the South, although it is occasionally found in Southern Illinois. It is a semi-parasitic plant that attaches itself to deciduous trees and "feeds" from that tree, although it also produces its own chlorophyll. The scientific name for mistletoe is Phoradendron, which in Greek means a thief ("phor") of a tree ("dendron"). Mistletoe in deed gets at least some nourishment from the trees on which they grow.
The sticky fruits are poisonous to man, but some birds can eat them. One or two berries are sufficient to cause severe poisoning or even death in a child. Therefore, any mistletoe you buy should have fake berries. This is definitely a time when artificial is okay. I tease that the sign of a good horticulturist is to know when and how to properly use fake plants!
From the earliest times mistletoe has been one of the most magical, mysterious, and sacred plants of European folklore. It was considered a bestower of life and fertility; a protectant against poison; and an aphrodisiac. Kissing under the mistletoe is first found associated with the Greek festival of Saturnalia and later with primitive marriage rites. For those who wish to observe the correct etiquette: a man should pluck a berry when he kisses a woman under the mistletoe, and when the last berry is gone, there should be no more kissing!
Holly is overall a much prettier plant. The deep, green holly leaves are shiny and spectacular. Their unique shape is found on many Christmas items, including cookie cutters. The red berries are also quite nice.
There are many different types of holly plants, but many are not winter hardy here. The most common holly grown in northern gardens is the Meserve Hybrid Hollies (Ilex x meserveae). Holly plants are either male or female. Both must be present in the near vicinity to ensure the female flowers and thus produce fruit. Generally we recommend planting one male plant to several female. To assure this, you must purchase your plants from a reputable source because there is no positive way to identify the different sexes until they flower.
Probably the best known of the holly trees grown in the United States is the American Holly. These are beautiful dense pyramidal evergreen trees. They are quite popular in Southern Illinois where they are more winter hardy. However, I do occasionally see a nice, big tree up here. In Champaign there are a couple very nice, old American Holly trees. Mature trees are quite large, growing 15-25 feet tall and 10 to 20 feet wide. If male and female trees are within 2 city blocks, they produce beautiful berries that last all winter.