When I think of parasites, I typically think of creatures such as tapeworms, fleas, ticks, and leeches—nasty invertebrates that drain the life out of us humans. Then, I might recall that some higher animals can also be parasites, such as the deep sea anglerfish. You’ve likely seen pictures of anglerfish, with their huge, pointy teeth in a large head, followed by a tapering body. When these fish mate, the male permanently attaches itself to the female and lives off her bloodstream for the rest of his life, his sperm his only contribution. (See National Geographic’s video of a particularly beautiful anglerfish species.)
“You don’t want to buy that lot—the trees have mistletoe!” Our realtor pointed at a shrubby mass growing among the branches high in the Ponderosa pine.
It didn’t look anything like the mistletoe I was familiar with, coming from California. There, the live oaks often support huge masses of mistletoe. And neither plant resembled the old plastic “mistletoe sprig” I inherited from my parents, that we hung in our doorway at Christmastime to encourage kissing. Curious, I did some research. It turns out that there are hundreds, if not thousands of barely-related species of parasitic plants called mistletoe.
Mistletoe is a holiday tradition. We decorate our doorways with it, where tarrying under a spring might bring you a kiss. Unfortunately, the kind of mistletoe growing along Colorado’s Front Range isn’t so romantic. Five different species of dwarf mistletoe infest pines, spruces and firs. Given enough time, an infected tree will eventually die.
All mistletoes are flowering plants that have given up a life of self-sufficiency to become harmful parasites. Dwarf mistletoes lack leaves, so they have little ability to make their own food from sunlight. Instead of extending their roots into the soil, they have root-like structures that penetrate under the bark, where they siphon off both water and nutrients from the host tree.
The female mistletoe plant produces sticky seeds. When the seed capsules are ripe, usually in late summer, they explode, expelling their contents at speeds up to 60 mph! The seeds can travel up to 60 feet, although 30 feet is more common. Wherever the seeds hit, there they stick.