Appearance
Hesperis matronalis is an herbaceous, biennial forb that grows up to 4 ft. (1.2 m) in height. It may be included in native wildflower mix packets. Always check the list of species in wildflower mixes.

Foliage
The alternate leaves are broadly lanceolate and sessile or born on short petioles. Leaves are 2-6 in. (5-15 cm) long and hairy.

Flowers
The showy, fragrant flowers vary in color from white to purple or pink and develop in the late spring. Flowers develop in clusters on 3 ft. (1 m) tall stalks.

Fruit
The siliques (long slender fruits) are 2-4 in. (5-10 cm) in length and contain a large number of seeds.

Ecological Threat
Many people mistakenly believe Hesperis matronalis is a native wildflower. It may be included in native wildflower mix packets. Always check the list of species in wildflower mixes. Habitats invaded by this plant include open woodlands, prairies, roadsides, ditches, and other disturbed areas where native plants are crowded out. Hesperis matronalis was introduced from Europe as an ornamental around the time of European settlement. It continues to be widely used as an ornamental and can be found throughout North America.

Resources

• Weed of the Week - USDA Forest Service
• Plant Invaders of Mid-Atlantic Natural Areas - National Park Service

Selected Images

Maps

Invasive Listing Sources

• Alberta Weed Control Act
• Colorado Noxious Weeds
• Commonwealth of Pennsylvania, Department of Conservation and Natural Resources, 1994.
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Hoffman, R. & K. Kearns, Eds. 1997. Wisconsin manual of control recommendations for ecologically invasive plants. Wisconsin Dept. Natural Resources, Bureau of Endangered Resources. Madison, Wisconsin. 102pp.
• Indiana Invasive Species Council - Invasive Plant List
• Indiana Terrestrial Plant Rule
• Invasive Plant Association of Wisconsin
• Invasive Plant Species of West Virginia
• Iowa Forest Invasive Plants
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• Kentucky Exotic Pest Plant Council - Moderate Threat
• Maine Invasive Plants
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture,  Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
• New Hampshire Prohibited Invasive Species
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Ohio Invasive Species Council
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Plant Invaders of Mid-Atlantic Natural Areas
• Rhode Island Natural History Survey
• Utah Noxious Weeds - Prohibited
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Invasive Species Strategic Plan and Volunteer Guidelines 2014
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References