Now that the California black oaks in Yosemite Valley have dropped most of their leaves, something strange has been revealed among the branches. Even though it is winter, big green leafy clumps of mistletoe are still growing up there. Mistletoe is a parasitic plant that survives by tapping into the water and nutrient supply in a living host plant. This mistletoe can produce some of its own food through photosynthesis, but gets all of its water from the oak host. Infestation of mistletoe doesn't usually kill the host, but it does weaken it and make it more vulnerable to other pests. Of course, this time of year you can't help but think of the seasonal tradition of kissing under the mistletoe. Watch out the next time you walk around Yosemite Village, you might be surprised how often you are standing under the mistletoe.
Leafy Mistletoe in the crown of a California black oak.