“A gift from the woods, but the forest pays the priceâ€
Oriental Bittersweet – (Celastrus orbiculatus)
Mary Paterson
Is it just a pretty yellow leafed vine with unusual scarlet berries climbing up a tree? It looks like a designer gift from Nature, just perfect for winding around a wreath or sticking into a dried arrangement. Or is it an unwanted weed, an exotic or alien invasive plant that if unchecked in the wild, will grow over other vegetation, shading it and preventing photosynthesis?
The 19th century was a period of global horticulture exploration and excitement. Many plants like Oriental bittersweet were innocently introduced onto our continent, only to escape into the wild. The terms alien, invasive, exotic, and weed are often used inter-changeably to describe unwanted plant species. Oriental bittersweet could be a poster child in the debate about whether it is responsible for a homeowner, especially a forest dwelling homeowner to plant an exotic invasive or even allow a volunteer one to abide on their property. As an ornamental plant, Oriental bittersweet is still widely sold for landscaping despite its invasive qualities. Many plants listed on the exotic invasive list are still sold today and are old favorites for gardeners.
Oriental bittersweet is in the staff-tree family (Celastraceae). It will girdle young trees and can even uproot them with its excessive weight. Its woody vine can grow up to four inches in diameter,r and I have seen the vine on a tree trunk hide the branches and leaves, giving the appearance of an Oriental bittersweet “treeâ€.
Oriental bittersweet has long tapering tipped young leaves, which become round tipped when mature with berries dangling along the branches. We also have a native American bittersweet (Celastrus scandens). It has leaves that are twice as long as wide and berries only at the end of the stem. Oriental bittersweet appears to be displacing our native bittersweet, and hybridization is suspected between the two species.
Should nurseries be allowed to grow, and big box stores allowed to sell plants that are documented to be invasive in the wild? If you see bittersweet for sale at a nursery or big box store, check to see if it is the American or Oriental, and please call this to the attention of the person in charge. Better yet, consider landscaping with only native plants. The American bittersweet is an excellent vine, but if you wish to consider alternative options, these might include trumpet honeysuckle ( Lonicera sempervirens), pipevine (Aristolochia macrophylla), or passion flower (Passiflora incarnate).
If you have some Oriental bittersweet that you wish to eliminate, the vines can be pulled out by the roots, but be thorough because it will also spread by root suckering. Cut the woody stem and immediately treat it with an herbicide containing glyphosate with a surfactant. An example is Roundup. Attempt this before the seeds develop to reduce dispersal. Oriental Bittersweet may be beautiful for your wreath in winter, but it is often spread by humans discarding the decorative fruit-bearing vines after being used for home decorations. Please consider buying artificial silk vines of bittersweet berries which are very pretty on wreaths, and the forest won’t pay the price.
Invasive plant species can be herbs, vines, shrubs, or trees. They are distinguished from other weeds by their ability to invade and spread into native ecosystems. They are typically non-native, but not all non-native species are invasive. Alien invasive plants are so successful because they have few or no native enemies, and they are undermining of the diversity of our native plant life, which affects our wildlife. Learn what plants are the worst offenders in your local area and eradicate them! Our wild forest lands need you. Our public lands and the wooded lots of absentee owners are breeding grounds for these exotic invasive plants. Perhaps we need to address this like we do with our litter problem. We need people to be the stewards of the local roadside ditches where many exotic invasive plants thrive and spread into the nearby fields and forests.
If you would like to learn more about invasive plants, more about Oriental bittersweet and other invasive plants, visit these websites. http://www.nps.gov/plants/alien/vines.htm or http://www.invasivespeciesinfo.gov/plants/main.shtml.
If you would like to help control invasive plants on our local public lands such as Grey Towers National Historic Site and The Delaware Water Gap National Recreation Area, please contact Mary Paterson at marymp@ptd.net or call 570-686-1138.
© Copyright 2010 Connections Magazine
