Invasive Alien Plant Species of Virginia

AlligatorweedCommon Reed ( Alternanthera(Phragmites australis philoxeroides) )

Description strongly suspected that a non- levels and nutrient loading in wet- Common reed is a tall perennial native, aggressive strain of the spe- lands are the best long-term protec- wetland grass ranging in height cies was carried to North America tion. from three to thirteen feet. Strong in the early 20th century. leathery horizontal shoots, called Control rhizomes, growing on or beneath Life History Once established, common reed is the ground surface give rise to roots Common reed spreads to a new area very difficult to completely eradi- and tough vertical stalks. These by sprouting from a rhizome frag- cate. stalks support broad sheath-type ment or from seed. New upright However, careful planning and leaves that are one-half to two stems grow from the rhizome each long-term management can yield inches wide near the base, tapering spring. Rhizomes spread horizon- varying levels of control. Herbicide to a point at the ends. The foliage is tally in all directions during the use in combination with burning gray-green during the growing sea- growing season. Flowering begins has generally proven to be the most son, with purple-brown plumes ap- in late June, and seeds are formed effective means of control, and re- pearing by late June. The plant by August. In early autumn, food sults in minimal disturbance to wet- turns tan in the fall and most leaves reserves move from leave and stems lands. Only a biodegradable herbi- drop off, leaving only the plume- to the rhizome system. The leaves cide that is licensed for use in wet- topped shoot. Big cordgrass die and fall off, with only the dead lands and non-toxic to animals can (Spartina cynosuroides), a non- brown vertical shoots remaining. be used. Because a healthy wetland invasive species, is sometimes con- The accumulation of dead leaves ecosystem is generally resistant to fused with common reed. It can be and stems, as well as the pervasive invasive species, long-term control distinguished from common reed by rhizome system, prohibits the of common reed depends upon res- its sparse flowering structure and growth of desirable plant species. toration of the health of the ecosys- long narrow leaves. tem. Threats Habitat Common reed has become a de- For more information on native Common reed thrives in sunny wet- structive weed in Virginia, quickly plant conservation, contact the Vir- land habitats. It grows along drier displacing desirable plants species ginia Native Plant Society at the borders and elevated areas of brack- such as wild rice, cattails, and na- address below. For information on ish and freshwater marshes and tive wetland orchids. Invasive Virginia's natural areas and natural along riverbanks and lakeshores. stands of common reed eliminate heritage resources, contact the Vir- The species is particularly prevalent diverse wetland plant communities, ginia Department of Conservation in disturbed or polluted soils found and provide little food or shelter for and Recreation's Division of Natu- along roadsides, ditches and wildlife. ral Heritage (see address below). dredged areas. Distribution Prevention Found throughout the temperate re- Minimizing land disturbances and gions of North America, common water pollution helps deter this in- reed is widespread in eastern Vir- vasive species. Land management ginia and also can be found in some practices that guard against erosion, western areas of the state. It is sedimentation, fluctuating water

For more information, contact the Department of Conservation and Recreation or the Virginia Native Plant Society.

Virginia Native Plant Society Blandy Experimental Farm 400 Blandy Lane, Unit 2 Boyce, Virginia 22620 (540) 837-1600 217 Governor Street, Richmond, Virginia 23219 http://www.vnps.org (804) 786-7951 http://www.state.va.us/~dcr/vaher.html