Does Mistletoe Have Thorns?

North American Mistletoe

• Phoradendron, a leafy mistletoe with white berries, is a genus with 200 known species found primarily on hardwood host plants throughout a wide cross-section of the country. These mistletoes are cultivated in U.S. Department of Agriculture plant hardiness zones 6 through 11.

Christmas Mistletoe

• Several phoradendrons share the common name, Christmas mistletoe (Phorandendron macrophyllum and Phoradendron serotinum subsp. Tomentosum); however, most members of the genus are used as -- and referred to as -- Christmas mistletoe and grow wild in their natural ranges. All phoradendrons have fleshy leaves, grow in clusters high in trees and produce small white, non-edible berries. Birds ensure a steady crop by eating and spreading these berries. Despite being parasitic, phoradendron is cultivated and harvested for holiday celebrations.

Parasitic Phoradendron

• This persistent, evergreen, seed-producing parasitic plant grows primarily on deciduous hardwood trees. It is especially obvious around the holiday season after the tree’s leaves have fallen and exposed mistletoe clusters. The plant skillfully steals minerals, water and most of its nutrients from the host tree; it’s parasitic on 110 tree species in the United States’ eastern half.

Plant Protection

• Few animals are interested in eating this plant in part because of calcium oxalate crystals in the leaves and stems -- this helps make mistletoe unpalatable for herbivores. Fine hairs, known as trichomes, often cover the surfaces of young mistletoe leaves, although these are typically absent on mature leaves. Close examination of young leaves with a magnifier reveals a fine layer of rigid-looking hairs. Sensitive humans experience discomfort when coming into contact with either.