ERIN NEGLEY | Staff WriterWhen you’re rocking around the Christmas tree looking for the mistletoe, did you know the best spot for a holiday kiss is under a parasitic plant named after poop?
Mistletoe might be a merry moocher but this plant lines hawk nests and feeds critters from porcupines to caterpillars. Humans should stick to kissing under the mistletoe because it’s poisonous to people. And while mistletoe isn’t common in Pennsylvania, that might change for Christmases yet to come.
American mistletoe
Picture mistletoe and you might imagine a branch with shiny green leaves, like the one hanging over the dance floor in a Justin Bieber video. This is one of more than 1,000 species of mistletoe, says Lea Johnson, associate director of land stewardship and ecology at Longwood Gardens. They vary widely, but all are semi-parasitic woody plants with aerial roots growing above the ground.
One of those, American mistletoe, or oak mistletoe, is found through the East Coast into the southern Midwest. The botanical name, phoradendron leucarpum, points to its white (leuca) fruit (carpum).
Mistletoe is a plant for the holidays and it’s also easiest to see at that time of year, when trees drop their leaves, Johnson says.
“In the winter, you’ll see it look like a fluffy bush or a little ball of stems high up in a tree,” she says.
American mistletoe prefers moist or wet habitat like a swampy forest and likewise is found on trees thriving in the same areas: red maple, black gum and oaks.
Mistletoe grows high in the top of trees because the seeds come from above. The white berries have a sticky juice that sticks around all the way through a bird. The seeds that come back out stick to the branches below. The name “mistletoe” comes from “dung on a twig” in Old English.
Parasitic plant
Once the seeds germinate, the plant grows root-like structures called haustorium, which grow into the tree tissue to borrow water and food. Mistletoe’s genus name points to this relationship: phora (thief) dendron (tree).
Because these tree thieves can photosynthesize, they’re not complete freeloaders, but semi-parasitic. Depending on the species, mistletoe can damage the host plant. American mistletoe may weaken branches, Johnson says.
While mistletoe takes from trees, it gives back to wildlife. It’s the host plant for great purple hairstreak butterfly caterpillars. Wildlife like squirrels, porcupines and chipmunks eat the leaves and birds eat the fruit. The fruit is poisonous to people, cats and dogs.
Finding mistletoe
Different kinds of mistletoe can be found throughout the country. One is the state flower of Oklahoma. Dwarf mistletoe can be found in western states and has been recorded in the bogs of northeastern Pennsylvania. On the East Coast, American mistletoe is most commonly spotted south of the Mason-Dixon line.
Emelie Swackhamer added a photo of mistletoe in a recent talk on new plant problems in Montgomery County. Only one of the professional arborists in her class could identify it.
That might change.
Swackhamer was leading the class as a horticulture extension educator with Penn State Extension. She recently spotted mistletoe in a tree at a rest area in the Delmarva peninsula, not too far from Lancaster County. It was notable enough for her to take a photo and wonder.
“Other things are moving their range northward,” she says. “I wonder if mistletoe will.”
Fresh mistletoe that isn’t growing in trees is also not easy to find in Lancaster County. BloomBox sold preserved mistletoe from Oregon this holiday season but the $7.95 bundles are sold out.
Grow your own?
It’s possible to grow your own mistletoe. Johnson had a few points to keep in mind. Each mistletoe species has a specific host plant. Mistletoe has male and female plants and only the female plants have berries. Because of mistletoe’s parasitic qualities, don’t try to grow it on a small tree.
While the plant is interesting, Swackhamer suggests being cautious about growing a plant that’s not common.
“There are a lot of silks and plastics that are good representations of the plant,” she says. “I’m not a big fan of silk or plastics as a rule but this is a case where it might be warranted.”
