This is the first in a series of articles discussing the ecology and management of select weed species. Most will be of agronomic importance, but our first species is one of popular interest for the Christmas season.
World of Weeds: Mistletoe
There are several species of mistletoe around the world, all of which are parasitic plants that attach to the stem of another plant. Mistletoes typically grow on trees and shrubs, but some species can grow on other types of plants, including grasses or even cacti. Mistletoes in the U.S. are typically found on fir, oak, pecan, and walnut trees. The mistletoe most likely to be found in Kansas is oak mistletoe.
Mistletoes have many branches with swollen nodes and opposite leaves (Figure 1). Flowers are not very obvious, but the berries are usually white, yellow, red, blue, or purple. Berries have a sticky pulp that sticks to the beaks of birds that eat them and helps them spread to new areas. Berries are toxic to humans, but there has been some interest in using berries of some mistletoe species for cancer treatments. Mistletoes are also grown commercially for Christmas decorations.
Figure 1. Mistletoe with berries. Photo by Joe Decruyenaere via Wikimedia Commons.
Mistletoes can reduce yield in systems such as tree nuts, pulpwood, and Christmas trees. They can be managed by removing infected branches or trees. Garlon (triclpoyr), glyphosate, and 2,4-D may provide short-term suppression of mistletoe, but they do not provide long-term control.
Stay tuned for upcoming articles in this new series, “A World of Weeds”. The next installment will be coming in January 2020. Do you have a particular weed species you’d like to know more about? Drop Dr. Lancaster a note at the email below or eUpdate Editor, Kathy Gehl, at firstname.lastname@example.org.
Sarah Lancaster, Weed Science Specialist
Mathiasen et al., 2008; Wood and Reilly, 2004; Watson and Martinez-Trinidad, 2006; Minko and Fagg, 2013.