But many invasive plants, especially recently introduced ones, are not listed on noxious weed lists and are still available commercially. We all need to be aware of invasive plants and avoid purchasing and planting them. A beautiful but aggressive invader from Europe, this hardy perennial degrades wetlands. Wetlands are typically one of the most biologically diverse habitats, supporting hundreds of species of plants and animals. Once purple loosestrife gets a foothold, though, wetlands are buried under a sea of purple flowers, choking out other native wetlands plants that wildlife depend on for food and shelter.
Purple loosestrife can also invade drier sites.
Purple loosestrife is a perennial herb in the loosestrife family, with a square, woody stem and opposite or whorled leaves. Plants are usually covered with down. Loosestrife plants grow from 4 to 10 feet high, and produce pink to purple flower spikes. These natives of China and Japan produce woody ornamental vines that climb vigorously, apparently limited only by the height of the tree. Both exotic wisterias flower in spring and produce a velvety seed pod.