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Door County, Wisconsin
16 April 2000
Gary Fewless, Cofrin Arboretum Center for Biodiversity
Olympus CL 2500L digital camera

Dwarf Mistletoe on Black Spruce.

Mistletoe (Arceuthobium pusillum)

The plant shown in the photograph is "Dwarf Mistletoe" (Arceuthobium pusillum). It is very small, often much less than one inch tall, and it is parasitic on the branches of Black Spruce (Picea mariana). Mistletoe does not produce chlorophyll (notice it is not green) and therefore does not photosynthesize. Instead, each plant sends out root-like structures that enter the branches of the tree and tap into the vascular tissues to get nourishment. The growth of Mistletoe plants causes the host tree to develop the unusual form known as a "witch's broom" shown in the larger photograph. If Mistletoe is very successful the host tree may eventually die, although this appears to take a minimum of several years. Most people think of Mistletoe as the plant that is hung from ceilings and doorways during the Christmas season. That species is known as American Mistletoe (Phoradendron sertoninum) and it grows in the southern United States.

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Last updated on April 15, 2014