Wednesday, December 15, 2010


Nature Watch
By Susan Thurn,
Cable Natural History Museum

Having just celebrated six months of wedded bliss, this holiday season brings on great feelings of love and opportunity for family celebration. It is a time filled with candy canes, colored tree lights, and mistletoe, just a bit of the many things we can enjoy at the holidays. I’ll never forget the time I was preparing a lesson plan for area schools on symbiosis, a word that describes the relationships between organisms in the natural world. I discovered then that mistletoe is a parasite. Mistletoe, a parasite? I always thought it was so ironic that a plant that brings love and joy into our lives was also a plant that uses other plants as a host by taking nutrients out of the tree. What a surprise!

Mistletoe is a partial parasite, as the plant is still capable of photosynthesis. They have a special root system, called haustoria, which grow down into their hosts. They extract nutrients from the trees upon which they grow.

The common dwarf mistletoe grows in northern Wisconsin. Not looking like most mistletoe plants we hang in our homes, this dwarf plant grows less than 3 centimeters tall. In spite of its size it often causes a very conspicuous irregular growth known as a “witch’s broom.” A witch’s broom is created by the mistletoe as it causes the tree to grow a compact mass of branches that resemble a broom that can reach 3-10 feet in size. Its main host is black spruce, but it also will parasitize red, white, and jack pine and balsam fir.

To some, mistletoe might be considered a negative part of a forest, but actually mistletoe does have some benefits in many ecosystems. The density of the growth can provide habitat to birds and other animals. Some species of mistletoe can cause the host plant to grow more berries, increasing reproductive success and providing food to other animals.

Mistletoe has a history that is rich in human tradition that goes all the way back to Greek culture. Throughout time mistletoe was thought to bestow life, protect against poison, and increase fertility. It was also thought to ward off evil, or bring peace, as well as provide a prediction of happiness and long life. Mistletoe can certainly bring magic to this season’s holiday joy. May you all enjoy a wonderful, festive holiday, and be sure to find your way under the mistletoe!

For over 42 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility and exhibit, On Lake Owen: The Art of Walter Bohl, in Cable at 13470 County Highway M. Also find us on the web at to learn more about our exhibits and programs.

No comments:

Post a Comment