Stem

  • Up to 6 ft. tall, 4-5 sided, covered with short hairs and often branched; multiple stems arise from root crown
Photo of Purple loosestrife

Leaves

  • Mostly opposite or whorled, narrow to lance-shaped, 2-6 in. long, smooth edges (margins), lack hair (glabrous) to hairy; NO leaf stems (petioles)
Photo of Purple Loosestrife

Flower

  • Showy; clustered on stalks at the tips of branches; 5-7 pink to purple petals surrounding a yellow center; petals are less than 0.5 in. long, each have a dark midvein and appear wrinkled or crushed
Photo of Purple loosestrife

Root

  • Taproot with some spreading roots; can associate with nitrogen-fixing bacteria
Photo of purple loosestrife

Other

  • Grows best in wet areas; often found in marshes and along the edges of pond and waterways; known to occur in Storey and Washoe counties
  • Perennial; reproduces by seed and stem fragments
  • Historically used as an ornamental plant but has escaped cultivation
 

Control

  • Repeated hand-removal of individual plants including roots can be effective; DO NOT mow
  • Several biological control agents are available
  • Apply metsulfuron to actively growing plants; glyphosate or triclopyr at bloom; imazapyr from bloom until killing frost 
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Nevada Noxious Weed Field Guide – Purple loosestrife, Extension, University of Nevada, Reno, Field Guide

Learn more about the author(s)

 

Also of Interest:

 
Nevada’s Priority Agricultural Weeds: Hoary Cress
Plants commonly referred to as hoary cress (Cardaria sp.), or short whitetop, are one of three different but closely related perennial forbs. The Cardaria species are widespread across all eleven Western states, including every county in Nevada.
B. Schultz, S. Foster 2021, Extension, University of Nevada, Reno, SP-21-03
African mustard plant
Nevada Noxious Weed Field Guide – African mustard
African mustard is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., H. Kratsch, Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of common crupina stem
Nevada Noxious Weed Field Guide – Common crupina
Common crupina is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of Common St. Johnswort plant
Nevada Noxious Weed Field Guide – Common St. Johnswort
Common St. Johnswort is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
Photo of crimson fountaingrass plant
Nevada Noxious Weed Field Guide – Crimson fountaingrass
Crimson fountaingrass is a noxious weed that has been identified by the state of Nevada to be harmful to agriculture, the general public, or the environment. Learn more about this weed.
Blecker, L., Creech, E., Dick, J., Gephart, S., Hefner, M., Kratsch, H., Moe, A., Schultz, B. 2020, Extension, University of Nevada, Reno, Field Guide
 

Associated Programs

master gardeners in garden

Master Gardeners of Washoe County

Master Gardeners provide free, research-based horticulture information to Nevadans.

hands holding freshly picked carrots

Grow Your Own, Nevada!

Learn the secrets of high desert gardening

Master Gardeners at tabling event

Master Gardeners of Nevada

Program trains local gardeners to provide research-based horticulture information to Nevadans