By Adrian Higgins
Thursday, December 13, 2007
Do people kiss beneath the mistletoe to keep their minds off the plant itself? I ask this because if you were to get to know this white-berried shrub, love and joy might not be the upwelling emotions.
Many folks know that the berries and leaves are toxic, but less known, I suspect, is that the shrub grows high in the branches of trees. Where does it put its roots? They wander under the skin of its host, supping from the tree's veins. One or two mistletoe bushes in an otherwise healthy tree will deplete it, though not to the point of death. Look hard in the canopy of maples and oaks: That squirrel's nest, if green, may be a mature mistletoe working its macabre magic.
This sinister trait has resonated in cultures through the ages. In Greek mythology, Persephone unlocked the gates to the underworld with a wand of mistletoe. The ancient druids venerated mistletoe for its powers and held that when the plant was growing on oak trees, as opposed to apple, it was particularly sacred. The tradition of kissing beneath it, based loosely on Celtic lore, became popular in the 19th century along with other yuletide rituals.
Colonists left behind the European mistletoe but in Jamestown, at least, found an abundant American version. Although hardy to New Jersey, the American mistletoe is common only in the South and especially in lowland areas where its favored hosts grow. In Tidewater, it can appear with such abundance as to kill its hosts, said Lytton J. Musselman, a botanist at Old Dominion University in Norfolk.
Most clumps of mistletoe are found 20, 30, 40 feet aloft, grown from seeds that have either passed through the guts of birds or been rubbed into the bark by their beaks as they seek to clean off the sticky berry.
Many of the sprigs sold for the holidays hail from the Carolinas and another part of the country rife with mistletoe, central California. The San Joaquin and Sacramento valleys are particularly afflicted, said Ed Perry, a University of California extension agent in Modesto.
The species is drawn to streamside plantings of cottonwoods, ash, locusts and silver maples and has spread to residential neighborhoods in Modesto, he said. Trees that succumb to massive infestations, Perry said, have been neglected in other ways. The mistletoe, which has a vested interest in keeping its host alive, is probably not the main reason for a tree's decline.
In the greater Washington area, the plant is less common and rarely abundant enough to imperil its hosts. It is, I think, a treat to find mistletoe. Essentially a Southern plant, it ranges to southern Maryland counties on both sides of the Chesapeake Bay but is far more abundant on the Eastern Shore. Near the Pocomoke River, mistletoe "has become very common," said Lisa Garrett, owner of the Wild Bird Center of Bowie. She has noticed its spread from oak to maple trees, and it appears far more abundant than a decade ago.
This may be due to climate change, or warmer weather patterns at least. Stanwyn Shetler, a botanist with the Smithsonian Institution, said, "A warming climate is likely to bring mistletoe and many other Southern plants northward."
The keen-eyed heading south to Richmond on Interstate 95 will see it on trees. One of the most astonishing pockets exists in a quarter-mile area in Fairfax County, in the Fair Oaks area. In the established neighborhood of Greenbriar, south of Route 50, the plant is particularly abundant, said Harry Pavulaan, a federal government cartographer and avocational butterfly expert.
Roderick Simmons, a plant ecologist with the City of Alexandria, told me of an exciting discovery of a mature mistletoe in the middle of Old Town, not only in a well-traveled block of Victorian rowhouses but growing just four feet off the ground. I set out to find it, and there it was in the middle of a snow squall, sprouting robustly from a 20-year-old honey locust.
This specimen was special for two reasons. Simmons said this was the first record of mistletoe growing in Alexandria since the 1880s. And because it was so low, one could study it without climbing into a cherry picker. The Old Town mistletoe grows on the eastern side of its host, wrapping two-thirds around the trunk and measuring about 18 inches top to bottom. Its two dozen or so bright green stems erupt from the tree bark like straws, and the tree has callused around the larger ones. Young stems and leaves erupt from the gray bark as the mistletoe continues its spread from the hidden threadlike roots, called haustoria.
The plant is devoid of berries, so either it is a male mistletoe, which doesn't fruit, or the robins have beaten me to the punch.
Why do I want berries?
Horticultural authority Donald Wyman once wrote that the mistletoe "is not a garden plant," but he made that observation before we closed the gap between the garden and nature. I know of gardeners in England who cultivate their species on apple trees; why not seek to grow one on a maple, honey locust or one of its favorite hosts here, the black gum or tupelo tree?
If one could find a seed source (the sprigs sold for the holidays often contain robust but useless berries made of plastic), one could try to propagate it on a suitable host tree, though this is a hit-or-miss affair.
Pavulaan has harvested fallen berries beneath stands of mistletoe at this time of year, though his efforts to propagate them have been unsuccessful. He smeared the berries into tree bark at his former home in Herndon, to no avail, and he followed a recipe in which the berries are steeped in very hot black tea and allowed to soak for two days. This is supposed to emulate the seed's journey through a bird. Again, he failed to get germination. "I've heard the best way to do it is to have a bird that would eat the seeds, and then you collect the droppings," he said.
Musselman said he has successfully started seeds in the greenhouse by rinsing them with a solution of hydrogen peroxide. After they germinate, the seedlings can be taken to a tree and wrapped lightly in plastic to allow the haustoria to penetrate over the winter. He said a young branch would be a better choice than an older one because the thinner bark would be less of a barrier to the young mistletoe.
My desire to start a pet mistletoe goes beyond the idea of having a mythical and beautiful native plant illuminating the winter landscape; it might also contribute to the spread of one our loveliest butterflies. The larvae of the great purple hairstreak feed exclusively on the mistletoe and should be welcomed for their name alone. The adult, about the size of a quarter, sups nectar in the summer from the native shrubs buttonbush and summersweet, and its upper wing surfaces are a glittering iridescent blue.
Butterfly fanciers say the sight of it is a thrill. Both mistletoe and the hairstreak have been found on the Eastern Shore of Maryland. Denise Gibbs, a naturalist for Montgomery County Parks, says the area around the Blackwater National Wildlife Refuge near Cambridge is full of mistletoe and a good prospect for finding the butterfly in late June to late July and again in mid-September.
It is considered rarer on the Western Shore, but experts have counted the butterfly in Prince's George's, Calvert, Charles and St. Mary's counties.
Pavulaan said he was amazed to hear from a fellow member of the Washington Area Butterfly Club who reported two sightings in his neighborhood in Chantilly, far from the bay.
"To have the plant and the butterfly there is quite a novelty," he said, "because the great purple hairstreak is basically a butterfly of the deep South."
Richard Smith, another expert at the butterfly club, said the prospect of creating a sustainable hairstreak colony from lone garden mistletoe specimens is unlikely. However, if there are mistletoe-infested woods near your home, growing your own mistletoe may entice a female to fly in, lay eggs on it, "and voila, you will have little great purple hairstreaks developing on your property, and you will be helping this species' survival in a small way."