Appearance

Lamium amplexicaule is is a cool season annual weed in the mint family (Lamiaceae). It has square stems that reach 6-15 in. in height. Unlike many plants in the mint family, henbit does not have a strong or distinctive odor. Henbit has a fibrous root system.

Foliage

Leaves on the stem that are not associated with flowers have petioles. Upper leaves have no petioles and occur just below flower clusters. Both types of leaves are somewhat rounded, coarsely toothed, and occur in pairs on opposite sides of the stem.

Flowers

Flowers are about 1 1/2 inches long, purple, and have hairy bracts.

Fruit

Seeds are found in nutlike fruits (mericarps) and are light to dark brown.

Ecological Threat

Lamium amplexicaule can be found in thrives in cool, moist areas and occurs in yards, parks, roadsides, fallow fields, winter grain crops, pastures, and turf grass. It can be highly competitive in newly seeded areas. Lamium amplexicaule has been found to be an overwintering host for soybean cyst nematode. it is also an alternative host for corn earworm.

Selected Images

Maps

Invasive Listing Sources

• Invasive Plant Species of West Virginia
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• Kentucky Exotic Pest Plant Council - Moderate Threat
• Maryland Cooperative Extension Service.  2003. Invasive Plant Control in Maryland. Home and Garden Information Center, Home and Garden Mimeo HG88. 4 pp.
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• New Hampshire Invasive Plant Species Watch List
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Pacific Northwest Exotic Pest Plant Council, 1998
• WeedUS - Database of Plants Invading Natural Areas in the United States
• West Virginia Native Plant Society, Flora West Virginia Project, and West Virginia Curatorial Database System, September 3, 1999

References