You just never know when you might encounter invasive aliens intent on wreaking havoc in the neighborhood. Walking along the trail at Cullowhee Rec Center the other day, I saw them, lining the little creek that separates the park from the elementary school.
Oriental bittersweet in Cullowhee, 10/22/10
I thought I recognized the plants, but studied a bit when I got back home, and still think they are the noxious Oriental bittersweet, rather than the more well-behaved American bittersweet.
Oriental bittersweet has been identified as the one invasive plant* posing the greatest threat to the forests of the Blue Ridge Parkway, and volunteers crews are working to contain its spread.
The US Forest Service, Southern Research Station, published this description in 2004:
Oriental bittersweet (Celastrus orbiculatus), a woody vine with rounded leaves and small yellowish flowers, was introduced to the United States from Southeast Asia around 1860. The bright orange berries produced in the fall have made oriental bittersweet popular for wreaths and winter flower arrangements, but the pretty vine wreaks havoc on the trees and native plants of the Southern Appalachian forest. The vine can spread by root suckering, but is primarily dispersed by the birds and mammals that eat the berries - and sometimes by people using the vines to decorate. Oriental bittersweet easily proliferates in forest openings created by disturbance.
Asheville, North Carolina, is a hub for oriental bittersweet invasion. The vine is literally moving out along roads and rivers into the public lands that surround the city, and poses a real threat to forest trees and plants. Oriental bittersweet grows fast: the plant can cover tall trees in a season, causing them to collapse from the weight of the vines. Understory plants are smothered by the vines themselves or by lack of light.
The native version of the vine, American bittersweet (Celastrus scandens), looks very similar to oriental bittersweet, except that it flowers and produces berries at the end of stems, while oriental bittersweet produces berries where leaf and stem intersect. Not aggressive or particularly invasive, American bittersweet itself is under threat. Because it hybridizes so easily with oriental bittersweet, the genetic integrity of the native plant may be lost.
I spotted this pest last fall in a different form and a different place. If you ever go to Cashiers, you might know that rustic/chic produce market near the crossroads. About this time last year, they had stacks of bittersweet wreathes. Sure, they do look quite decorative.
I observed one pleased shopper purchasing a wreath. As the money changed hands, there was no word, no warning, about the invasive nature of the plant. And all it takes is one dusty old bittersweet wreath, tossed in the woods behind the house, to start a new infestation.
From what I learned since then, the state floated a policy several years ago to ban the offending bittersweet wreaths, but THE POWERFUL CRAFTERS LOBBY raised a stink, and pressured the state to back down.
Interesting how even a small, all but invisible, niche of the economy can become a special interest group steering government policy toward a questionable position of tacitly aiding and abetting this scourge.
As it stands now, the NC Dept. of Ag forbids transport of Oriental bittersweet beyond the 13 western counties of North Carolina. (As if the wreaths leaving that Cashiers market aren’t going far and wide!)
Bittersweet quarantine area (in red), per NCDA.
Researchers have actually looked into terminating the viability of those dried seeds on the bittersweet vines and wreathes. The hope was to deactivate the seeds without altering the appearance of the plant materials. No sort of heat treatment or chemical dip or clear spray was found to meet those criteria.
“Natural” options for control or eradication of Oriental bittersweet are few. The best approach is to uproot the plants. However, if a small amount of root remains in the ground, new shoots are liable to come up.
*The list of invasive plants threatening WNC ecosystems also includes:
Vining and bush honeysuckle
Bittersweet Along the Expressway
by Norbert Kraft
As if in retreat
from the unending lines
of cars jerking and
swerving from Manhattan
onto Long Island
the slender bushes
crawl up the wire fence
preserving the strip
of greenery from
the service road
and like wild animals
trapped in a zoo
peer through wire diamonds
with bright orange pupils.
by George Herbert
Ah, my dear angry Lord,
Since thou dost love, yet strike;
Cast down, yet help afford;
Sure I will do the like.
I will complain, yet praise;
I will bewail, approve;
And all my sour-sweet days
I will lament and love.