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Federal Noxious Weed
TDA Noxious Weed TPWD Prohibited Exotic Species Invasive Plant Atlas of the USNOTE:
means species is on that list.
Lythrum salicaria
Purple loosestrife
Synonym(s): Lythrum salicaria var. gracilior, L. s. var. tomentosum
Lythrum salicaria var. vulgare
Family: Lythraceae (Loosestrife Family)
Duration and Habit: Perennial Herb
Photographer: Bruso, George H.
Source: Native Plant Information Network
Description
Leafy, angular stems have crowded spikes of brilliant pinkish-lavender flowers at top, opposite or whorled, unstalked leaves below. Plant grows in dense patches. Flowers: 1/2-3/4" (1.3-2 cm) wide; petals 4-6, nearly 1/2" (1.3 cm) long, attached to a purplish calyx-like tube with several pointed teeth; stamens as many or twice as many as petals; flowers of 3 types, each with different stamen and pistil lengths. Leaves: 1 1/4-4" (3.1-10 cm) long, narrow, opposite, notched at base; lower ones downy, clasping the stem. Height: 2-7' (60-210 cm).
Native Lookalikes: Currently no information available here yet, or there are no native Texas species that could be confused with Purple loosestrife.
Ecological Threat: Purple loosestrife adapts readily to natural and disturbed wetlands. As it establishes and expands, it outcompetes and replaces native grasses, sedges, and other flowering plants that provide a higher quality source of nutrition for wildlife. The highly invasive nature of this plant allows it to form dense, homogeneous stands that restrict native wetland plant species, including some federally endangered orchids, and reduce habitat for waterfowl.
Biology & Spread: Purple loosestrife enjoys an extended flowering season, generally from June to September, which allows it to produce vast quantities of seed. The flowers require pollination by insects, for which it supplies an abundant source of nectar. A mature plant may have as many as thirty flowering stems capable of producing an estimated two to three million, minute seeds per year.
This plant also readily reproduces vegetatively through underground stems at a rate of about one foot per year. Many new stems may emerge from a single rootstock of the previous year. "Guaranteed sterile" cultivars of purple loosestrife are actually highly fertile and able to cross freely with purple loosestrife and with other native Lythrum species. Therefore, outside of its native range, purple loosestrife of any form should be avoided.
History: The first mention of L. salicaria in North America was in 1814 in Pursh's Flora Americae Septentrionalis, and it was thought to have been introduced either in ship ballast or with sheep wool to the eastern coast. It then spread slowly along rivers, canals and ditches and moving westwards along the Erie Canal. It was not until the 1930s that the first monocultural populations and rapid expansion of this species westward were observed; and was first reported as a problematic weed in Quebec.
In the 1940s, beekeepers and honey producers began to realize the potential of using this species as a bee forage, and reports reports of beekeepers deliberately spreading its seeds along streams and rivers in order to increase the density and number of flowering populations (Thompson et al., 1987). By 1985, L. salicaria was recorded in all states of the USA.
U.S. Habitat: Purple loosestrife occurs in freshwater and brackish wetlands. It is a successful colonizer and potential invader of any wet, disturbed sites in North America. Associated species include cattails, rushes, sedges, and reeds.
Distribution
U.S. Nativity: Introduced to U.S.
Native Origin: Europe
U.S. Present: AL, AR, CA, CO, CT, DE, IA, ID, IL, IN, KS, KY, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NV, NY, OH, OK, OR, PA, RI, SD, TN, TX, UT, VA, VT, WA, WI, WV, WY
Distribution in Texas: Spare reports from the Panhandle, north and east regions of Texas.
Mapping
Invaders of Texas Map: Lythrum salicaria
EDDMapS: Lythrum salicaria
USDA Plants Texas County Map: Lythrum salicaria
Native Alternatives
Native species of Liatris (blazing star) have showy pink-purple flower spikes and are an important nectar source for many native species of butterflies and other insects.
Other alternatives include:
Joe Pye weed (Eutrochium dubium)
Cardinal flower (Lobelia cardinalis)
Blue vervain (Verbena hastata)
New York ironweed (Vernonia noveboracensis)
Fall obedient plant (Physostegia virginiana)
Management
Purple loosestrife also spreads vegetatively. Buried stems harbor adventitious buds with the ability to produce shoots or roots. Disturbance to the plant by stomping and breaking underground stems, or breaking off stems or roots during incomplete plant removal, does initiate bud growth.
Cutting alone is not a control option for purple loosestrife. Shoots and adventitious roots will develop. Cutting late in the season reduced shoot production more than mid summer cutting, indicating that carbohydrate reserves could not be restored for next years growth.
Text References
Bailey, L.H. and E.Z. Bailey. 1977. Hortus Third: A Concise Dictionary of Plants Cultivated in the United States and Canada, MacMillan Publishing Co., Inc., New York.
Balogh, G. 1986. Ecology, Distribution and Control of Purple Loosestrife (Lythrum salicaria) in Northwest Ohio. Thesis for Master of Science Degree from Ohio State University. 107 pp.
Stuckey RL, 1980. Distributional history of Lythrum salicaria (purple loosestrife) in North American Bartonia, 47:3-20.
Swearingen, J., K. Reshetiloff, B. Slattery, and S. Zwicker. 2002. Plant Invaders of Mid-Atlantic Natural Areas. National Park Service and U.S. Fish & Wildlife Service, 82 pp.
Thompson, D.Q., R.L. Stuckey and E.B. Thompson. 1987. Spread, Impact and Control of Purple Loosestrife (Lythrum salicaria) in North American wetlands. USFWS, Fish and Wildlife Research No. 2. US DOI, Washington, D.C. 55pp.
Online Resources
APWG WeedUS Database
https://www.cabidigitallibrary.org/doi/10.1079/cabicompendium.31890
Search Online
Google Search: Lythrum salicaria
Google Images: Lythrum salicaria
NatureServe Explorer: Lythrum salicaria
USDA Plants: Lythrum salicaria
Invasive Plant Atlas of the United States: Lythrum salicaria
Bugwood Network Images: Lythrum salicaria
