Date of this Version
Proceedings of the 23rd North American Prairie Conference, August 2012, University of Manitoba in Winnipeg.
The Prairie Naturalist 46: 120-122. August 2014
Oriental bittersweet (Celastrus orbiculatus Thunb.; hereafter OB) is an invasive, woody vine that has been expanding its range westward in North America since its introduction from East Asia in the mid-1700s for horticultural purposes (Albright et al. 2009, United States Department of Agriculture [USDA] 2012). Although typically a woodland problem in the United States (McNab and Meeker 1987), OB can invade grassland habitats (Fike and Niering 1999), likely sprouting from seeds dropped by birds and mammals (McNab and Meeker 1987, Greenberg et al. 2001, Sarver et al. 2008) and often developing into large, shrub-like tangles of intertwining stems (Fike and Niering 1999). Once established, OB can easily out-compete native plants because of its superior growth rate, high seed production, and high rates of seed dispersal and germination (Greenberg et al. 2001, Leicht and Silander 2006, Leicht-Young et al. 2007a, b).
Oriental bittersweet was first reported in Minnesota in 2010, although it likely was present previous to that date (Minnesota Department of Agriculture [MDA] 2012, USDA 2012). Oriental bittersweet occurs mainly along highway corridors and has converted the forest-grassland edge habitat into OB monoculture jungles, overrunning and killing shrubs and trees. In many areas in southeastern Minnesota, OB has invaded deeper into grasslands along fence lines and around isolated shrubs and artificial nest boxes placed for eastern bluebirds (Sialia sialis; N. D. Mundahl, Winona State University, unpublished data).