ROOM TO GROW: Interesting holiday finds in the great outdoors

I was recently in search of interesting plant material to display for an educational exhibit. Of course, I wanted it to have some relevance, so I decided to go with a holiday theme.

The hollies from my father's house were pretty and the cedar was quite aromatic. However, it was the reindeer moss and mistletoe that were the most interesting finds.

MISTLETOE

Mistletoe is synonymous with the holiday season and smooching sweethearts. This flowering plant has been associated with the Yuletide season for centuries. While the folklore with mistletoe has early beginnings, it was during the 1500s that the tradition of kissing under mistletoe developed as William Irving wrote that a young man should pluck a berry each time he kisses a girl beneath the mistletoe.

The collective term "mistletoe" refers to any of more than 200 species of semi-parasitic shrubs found worldwide. It lives throughout the southern United States, from the Atlantic Coast to California, and on every continent except Antarctica.

The leathery green leaves contain chlorophyll that allows it to make its own food. However, the root-like anchors suck water and nutrients from living trees. This is particularly problematic on trees that are weakened by some type of stressor.

Mistletoe grows high in the branches on a number of different tree species; including cottonwood, maple, oak and other deciduous hardwoods. American mistletoe has big leaves -- about the size of your thumb -- and small white berries.

The berries have a sticky, glue-like substance inside with little strings attached to its indigestible seeds. Although eating mistletoe berries may be potentially lethal for humans, birds seem to be immune to their toxic effects. This immunity allows for mistletoe's dispersal and propagation.

Mistletoe grows slowly at first, sometimes taking years for seeds to be produced. Healthy trees are able to tolerate small mistletoe infestations, but individual branches may be compromised and susceptible to wind or cold injuries. Heavy infestations may reduce the overall plant health or even kill a weakened tree.

The best way to control the growth and spread of mistletoe is to prune it out of trees. Cut out infected limbs 1 to 2 feet below the infection point. If you don't remove the "roots" of the mistletoe, regrowth will likely occur. If the mistletoe is located on a main limb or trunk, removing the top of the mistletoe and wrapping the cut with an opaque plastic to prevent sunlight may be beneficial.

REINDEER MOSS

Another interesting find in the natural world is reindeer moss. Not a plant -- or even a moss, as the name implies -- reindeer moss is in fact a lichen.

Lichens, often overlooked in the natural world, are a symbiotic partnership of fungus and algae. The algae convert sunlight into usable energy through photosynthesis, while the fungi absorb vital nutrients and provide protection. Ultimately, both species benefit, and often neither would be able to survive on its own.

Lichens come in many different colors, textures, shapes and sizes. They are really quite fascinating, if you start paying attention. They can cover trees, bushes, walkways, brick walls -- you name it and a lichen can likely grow on it.

One challenge is that lichen are sensitive to air pollutants. As pollution, and particularly heavy metals, increase in the environment, this important food source is threatened.

Reindeer moss, a fragile grey-green lichen, grows in puffy mounds along the ground. Interestingly, it is often an indicator of poor soil conditions. In the northern alpine and arctic environments, reindeer moss is an important food source for caribou and, you guessed it, reindeer.

Let's hope Rudolph and his buddies steer clear of the mistletoe and find plenty of patches of reindeer moss on their way south next week!

Wishing you and yours peace this holiday season.

Contact Karol Kelly at karolk@uga.edu.

This story was originally published December 16, 2015 at 9:45 PM.