Mistletoe: The Poisonous Plant We Love To Hang At Christmas

European or Common mistletoe, Viscum album

For centuries, people have been hanging mistletoe as an expression of love and romance. Unfortunately though, the relationship is one-sided, as the plant doesn’t return the same feelings. Why?  Because mistletoe contains a Christmas cocktail of toxins that when ingested can be harmful to humans and pets. I’d advise keeping it out of reach if you’re planning to make it part of your holiday décor.

WHAT IT IS

For all its romantic associations, mistletoe is no loving plant. In fact, it is parasitic. That means it specializes in attaching to the branches of a tree or shrub and penetrating it to steal water and other nutrients.

And while its deep green, ball-like form adds a touch of ‘life’ to bare branches, once mistletoe gets its roots into a plant it immediately begins to destroy it. This usually requires the removal of all infested limbs and in some cases entire trees in which there are large-scale invasions.

Attractive but parasitic bright green clusters of European mistletoe

IT LIKES TO SPREAD

As if that weren’t bad enough, mistletoe seeds are also easily dispersed. Those pretty white berries that add a festive touch to the sprig? Birds love them. As they’re carried away, the berries’ sticky pulp drops onto the upper branches of shrubs and trees, sowing seeds on other species.

All told, it can take up to two years for a mistletoe to fully develop within a plant. Once firmly rooted, it sends out aerial shoots that typically weaken and distort the host. Sometimes it even kills it.

WHAT HAPPENS IF I EAT MISTLETOE?

There are two main species of mistletoe, Viscum album (European or Common mistletoe) and Phoradendron (American or Oak mistletoe). Both contain a mix of toxic compounds in their stems, leaves and berries that, if ingested, can be harmful to humans and pets.

However, of the two, Viscum album is the more toxic. Its pairs of smooth, oval shaped leaves and clusters of sticky white berries contain a mix of chemicals that include poisonous amounts of the alkaloid tyramine. Tyramine can cause stomach upset, nausea and vomiting, blurred vision, blood pressure changes and in rare cases even death.

The oval leaves and white berries of Viscum album

Not to worry (too much), though. In North America, Viscum album is a rarity unless it has been purposely transplanted (California being the exception.) Instead, our own native species, Phoradendron, populates our forests.

American mistletoe has shorter and broader leaves than the European species and larger clusters of white berries. It also secretes a toxin, in this case phoratoxin, that causes the same symptoms as tyramine. But happily, it’s to a lesser extent.

The paddle-shaped leaves of Phoradendron

In fact, although until recently American mistletoe was widely considered to be as poisonous as the European species, downing a few berries is likely to lead to no more than a stomachache. According to the National Capital Poison Center’s recent studies describing American mistletoe exposures (mainly by young children at Christmas), you’d have to eat a whole lot of berries to experience these reactions. The vast majority of patients who ate parts of the plant had no symptoms. Moreover, there were no fatalities, even among those who had swallowed mistletoe on purpose.

POISONING IN DOGS AND CATS

When it comes to pets, small amounts of mistletoe most likely will cause no more than mild gastrointestinal distress. However, if your cat or dog accidentally consumes large amounts of the plant, it could lead to abnormal heart rate, collapse or even seizures. If you suspect your pet has eaten mistletoe, contact your veterinarian or Pet Poison Helpline for treatment recommendations.

Mistletoe is most harmful to small children and pets/Photo credit: Michael Pettigrew

MISTLETOE AS MEDICINE

Perhaps as a result of its toxicity, Viscum album has been used by herbalists as medicine for centuries. This includes using it to improve circulatory and respiratory problems and to treat a variety of conditions including seizures, hypertension, headaches and arthritis. More recently, mistletoe extract has shown promise in stimulating the immune system in some limited laboratory studies. Today in Europe it is also being used as a cancer treatment.

(Although the United States FDA has not approved mistletoe as a treatment for cancer or any other medical condition, it is nonetheless being studied in clinical trials.)

Mistletoe is currently being harvested in Europe for its cancer-fighting properties

THE TAKE-AWAY

Used safely, mistletoe may do a lot more for humankind than just providing a romantic canopy. As we learn more and more about what plants can do, mistletoe’s powerful medicinal qualities are something to celebrate in addition to its decorative properties. Something to think about next time someone reaches in for a kiss under its branches.

 

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When I was a teen, a French girl came to live with us for the summer. She caused quite a stir in conservative Delaware with her cigarette jeans, lace-up wedge espadrilles and oversized red glasses. That being said, what I remember most was her preference for a men’s cologne named Pino Sylvestre. Whenever she brushed past, a wisp of fresh, forest smell followed in her wake. Continue reading

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Longwood Gardens Gets Dressed Up For The Holidays

Longwood Gardens 2016 Photo credit: Here By Design

For a long time, Pennsylvania’s Longwood Gardens has been my go-to destination for the holidays. The magnificent property features over 1,077 acres of formal gardens, woodlands and meadows that change with each new season. Located at the heart of the gardens is one of my favorite places, the huge glass and steel Orangery. It is here, in this 1920’s-era greenhouse, that my holidays come alive in the horticultural extravaganza known as A Longwood Christmas.

When it comes to inspiring, it doesn’t get much better than Longwood Gardens. From late November to just after the New Year, the Orangery is filled with holiday-themed displays, including hundreds of decorated trees, rare plants and miles of seasonal flowers. Covering nearly four acres of greenhouses, the colorful blooms and exotic specimens are all embellished with millions of twinkling lights.

At my most recent visit, each turn of the corner revealed a new color scheme, plant display and fragrance; a heady combination that made for a constantly changing experience.

This year’s display showcases over 6,000 seasonal plants.

 

THE TOUR

To begin their tour of the Orangery, visitors enter through the majestic East Conservatory. In this huge, vaulted space the predominantly red, white and silver horticultural displays are punctuated by gurgling fountains and tiered pools all linked by rushing streams of water. A warm, earthy aroma mixed with flower fragrances permeates the space.

This year’s exhibit in the East Conservatory features formal flower beds and manicured pathways fringed by generous drifts of fragrant paper white narcissus, euphorbia ‘Diamond Frost’, miniature arborvitae, ferns and snow white cyclamen. A permanent display of giant palms and other tropical plants provides the backdrop for the seasonal flowers.

A number of beautiful Christmas trees are situated within the beds and along the walkways.

Close-up of some of the stunning detail on each of the trees.

At the end of the East Conservatory is the largest tree of the exhibit, an 18-foot Douglas fir. The giant tree is encircled by bright green ferns that point up the tree’s deep red ribbons and other natural decorations.

Behind the East Conservatory is the Main Conservatory exhibit. The dramatic space consists of a pair of manicured lawns encircled by seasonal plantings and massive stone columns wreathed in ivy. Giant hanging baskets of scarlet poinsettias are suspended high above the display.

Lawn in the Main Conservatory

On a bright winter day at Longwood Gardens, sunlight filters down through the vaulted iron and glass ceiling and traces a path across the lush borders of this iconic space.

I’ve always loved how, in the far corner of the Conservatory, the color palette shifts from traditional reds and greens to vibrant yellows and blues. This year’s exhibit includes a healthy dose of bright yellow twig dogwoods, orange birds of paradise, miniature lace-cap hydrangeas, soft pink poinsettias and spiky blue coleus.

Directly behind the East Conservatory is Longwood Gardens’ Exhibition Hall. Small jets of water spout from a sunken area in which ‘floats’ a grand central tree decorated in bright red poinsettias and snow white orchids.

The soft purple blooms of bougainvillea growing along the Conservatory’s rafters set up a strong color contrast with the bright red poinsettias.

After the brilliant colors of the main Conservatory, the minty green Acacia Passage provides a cool refuge. It is best known for the lacy tendrils of cinnamon wattle trees that travel up its walls and cascade down from the ceiling. Potted white hydrangeas underplanted with trailing ivy lead the eye down through the narrow space.

Located at the far end of the Acacia Passage, the Orchid Room (part of Longwood Gardens’ permanent display) features over 500 fragrant orchid varieties. An orchid grower replaces plants three times a week to ensure a continuous colorful exhibit.

Orchid vanda ‘Sansai Blue’ hangs in the Orchid Room

A right turn takes you to the  Mediterranean Garden, which showcases plants from regions around the world with Mediterranean-like climates. The central tree is decorated in bright-colored balls that echo the warm-climate plantings.

Kniphofia uvaria, commonly known as Red Hot Poker

In the Bonsai Hall, a dramatic red and green wreath hangs in stark relief against the pale grey wall.

At the far end of the Mediterranean Garden is the Palm House, which is designed to resemble a tropical rain forest. The three-layered garden showcases Longwood Gardens’ wide variety of palms, cycads and tropical groundcovers. This tropical tree displays Aglaonema ‘Osaka’ (a variety of Chinese evergreen) on a custom-made form topped with flower heads pulled from Longwood’s palm collection.

Close-up of the Palm House tree

One of the most dramatic trees of all is housed in the Xeriscape garden, a stunning mix of grey, white, silver and red drought-tolerant plants.

Close-up of the succulent tree

At Longwood Gardens, even the mini pitcher plants are decorated for the holidays.

For more information on the exhibit, go to A Longwood Christmas.  The display is open from now until early January.