It can seriously impact a wetland area in just a few seasons. Each mature plant produces over a million seeds and can resprout from a small part of a root or stem. No wildlife species are known to use this plant, and the dense thickets of dead stems deter waterfowl and other wildlife access to waterways. Surveys in 1997 and 1998 located isolated plants and moderate populations along the Truckee River from Sparks to Nixon. It has the potential to destroy riparian habitat along the river all the way to Pyramid Lake and Stillwater Wildlife Refuge if not controlled immediately.
Individual flowers have five or six pink-purple petals surrounding small, yellow center.
Each flower spike is made up of many individual flowers. Flowers appear in July and may continue into September. Each mature plant can produce up to 2.7 million seeds annually. As tiny as grains of sand, seeds are easily spread by water, wind, wildlife and humans. Germination can occur the following season, but seeds may lay dormant for several years before sprouting.