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A look under the mistletoe By Morgan Rothborne Dec 18, 2022 01:00 AM A A Kristi Mergenthaler, stewardship director at Southern Oregon Land Conservancy, points out a patch of mistletoe on an oak tree Wednesday at Pompadour Bluff outside of Ashland. [Jamie Lusch / Mail Tribune] Mistletoe grows on an oak tree at Pompadour Bluff outside of Ashland. [Jamie Lusch / Mail Tribune] Interwoven in Christmas tradition, mistletoe hangs from door posts by red ribbons, adorns Christmas movies and flits through holiday music. In the oak stands of Southern Oregon, the parasite is omnipresent and grows throughout the valley largely unnoticed the rest of the year. “Is it a special plant that encourages kissing, that is sacred in many cultures? Or is it an evil plant, that sucks the vitality out of oak trees? Or is it both?” asked Kristi Mergenthaler, stewardship director at the nonprofit Southern Oregon Land Conservancy. Mistletoe is native to Southern Oregon, and includes more than a single species. The Klamath-Siskiyou region is a hot spot of mistletoe diversity, Mergenthaler explained. The species most common in the valley is oak mistletoe, genus Phoradendron — tree thief. Oak mistletoe lives by making its food from sunlight and creating oxygen in exchange, as many plants do. But all its life it steals its water from the oak tree. “For a long time, people were like ‘Well, does it hurt the oaks?’ A lot of oak trees have those big, round, green balls,” she said. “People love oak trees, which I think is so marvelous. I also think parasites and partial parasites kind of get a bad rap — from our perspective” “It’s a hemi-parasite,” said Mergenthaler. “Other ones that people tend to know are beautiful flowers — like Indian paintbrush is a partial parasite. It’s not bad or good really; it’s just a strategy of how to survive as an organism.” Mergenthaler compared the plant’s position in ecology to the way people often experience nature shows — fence-sitting and switching sides, rooting for predator one moment and prey the next. It can be irresistible for people to want the predator to eat and the prey to live, but in nature good or bad can become intangible as life and death are folded into one cycle of motion outside the bounds of black-and-white distinctions. “It just depends on what your objective is,” she said. Dwarf mistletoe, a denizen of conifer trees, is resented by foresters because it hinders the development of trees and thereby their profitability, she explained. But the large brooms of the plant are beloved by some species, including an old nemesis of the logging industry — the northern spotted owl. In the winter, oak mistletoe produces berries that provide a rich source of fresh food through those cold, slim months for overwintering birds — robins, bluebirds, waxwings and Townsend’s solitaires. “Last week I was watching a bunch of bluebirds go from one oak mistletoe bundle to another,” said Mergenthaler. Mistletoe also can be a host plant for butterflies, performing the same function for the great purple hairstreak butterfly as milkweed does for the monarch — the only plant where the female will lay her eggs and the sole source of sustenance for the caterpillars. Some landowners express devotion for their oaks by removing mistletoe to protect the tree, which sometimes injures the tree and, potentially, the bluebirds. “Our beautiful bluebirds — they’re declining, they’re not doing so well,” she Mergenthaler. A recent long-term study, she explained, paints a more nuanced picture of how oak mistletoe lives with oak trees. “The study found the impacts are negligible. Oak mistletoe tends to be more like episites, the plants that grow on trees like lichens and mosses,” said Mergenthaler. Homeowners still suspicious of the hemi-parasite and eager to remove the plant also have to contend with how it spreads. “The birds are the ones that spread the mistletoe from tree to tree,” said Mergenthaler. “They eat the berries, and then when their droppings come out, the fruit turns into this sticky little seed mat that sticks to the tree branches.” Oak trees are spread by birds, too. Blue jays bury acorns for later, then like people with car keys, they forget where some of their stashes lie, said Mergenthaler. New trees grow from the forgotten winter’s hoard. European druids believed mistletoe was sacred, she explained, as a bridge between the land and the heavens. Perhaps they were describing in spiritual terms something tangible. Butterflies and birds touch the ground and the sky, and they rely on mistletoe. Even though harvesting mistletoe can harm trees, if it is done carefully and in moderation, said Mergenthaler, those looking to bestow a sprig of the partial parasite can safely pull off a little for Christmastime kisses. Reach Mail Tribune reporter Morgan Rothborne at [email protected] or 541-776-4487. Follow her on Twitter @MRothborne.