Ah, Christmas.

Chestnuts roasting on an open fire.

Sleigh bells ringing.

Mommy kissing Santa Claus under a tree-killing parasitic plant.

Mistletoe may be a festive and romantic Christmas tradition, but the plant has a sinister side: It has long infested native trees throughout the Tucson area.

And its journey from berry to branch is unlikely to stir passions, either.

"It spreads from birds eating the berries, then pooping the seeds onto trees," said Jason Elam, an employee of Desert Survivors, a native-plant nursery. "The seed has a sticky substance that helps it cling to the bark, and with moisture the seed sprouts very quickly."

A healthy tree that's pruned correctly can survive a mistletoe infestation, but an ailing tree or one covered in massive clumps of mistletoe might die if it's not treated by an arborist.

Unlike the small boughs of leafy mistletoe sold at holiday time, Tucson's mistletoe manifests itself as a tangle of segmented tendrils emanating from a lump on the branch where the seed has rooted. Although birds like to eat the red or white berries, the fruit and the foliage are toxic to humans.

"The only thing you can do is cut pretty much the entire branch that the mistletoe is on," Elam said. "Where the tree is swollen, that is not the entirety of the mistletoe. Sometimes there are still bits of it further out into the branch. As long as you remove the basal part of the plant, the swollen part of the branch, there's a really good chance it's not going to come back from that area."

Dolores Rivard, of the University of Arizona Cooperative Extension Master Gardeners Program, said: "The average homeowner, if they have the proper tools and use safety precautions, can remove it. I have no idea why this is supposed to be so romantic when it's a nuisance."

Mistletoe basics

As a parasitic plant, mistletoe grows on the branches or trunk of a tree and sends out roots that penetrate into the tree and take up nutrients, although it's capable for growing on its own and can produce its own food by photosynthesis.

There are two types of mistletoe. The mistletoe that is commonly used as a Christmas decoration (Phoradendron flavescens) is native to North America and grows as a parasite on trees in the West, as well as in a line stretching from New Jersey to Florida.

The other type of mistletoe, Viscum album, is of European origin. The European mistletoe is a green shrub with small, yellow flowers and white, sticky berries that are considered poisonous.


Celtic priests, known as druids, revered the oak tree and the mistletoe that grew on it. At the winter celebration of Samhain, the sacred oaks were bare except for the green boughs of mistletoe, and this was taken as a sign of eternal fertility. The Celts placed a sprig of mistletoe above the doors of their houses, and its sacred nature prohibited fighting beneath it. This evolved over centuries into the custom of kissing underneath the mistletoe at Christmas.

The Greeks also thought it had mystical powers, and down through the centuries it became associated with many folkloric customs. In the Middle Ages and later, branches of mistletoe were hung from ceilings to ward off evil spirits.

In Europe, they were placed over house and stable doors to prevent the entrance of witches.


Kissing under the mistletoe is first found as being associated with the Greek festival of Saturnalia, and later with primitive marriage rites because it was believed to bestow fertility.

In Scandinavia, mistletoe was considered a plant of peace, under which enemies could declare a truce or warring spouses could kiss and make up.

In 18th-century England at Christmastime, a young lady standing under a ball of mistletoe, brightly trimmed with evergreens, ribbons and ornaments, could not refuse to be kissed. Such a kiss could mean deep romance or lasting friendship and good will. If the girl remained unkissed, she could not expect not to marry in the following year.

Did you know

Trees most affected by mistletoe in Tucson are mesquite, palo verde, acacia and ironwood.

Contact reporter Kimberly Matas at kmatas@azstarnet.com or at 573-4191.