Appearance
Galeopsis tetrahit is an herbaceous annual that grows to be 1-3 ft (0.3-0.9 m) tall. The simple to branched stems are square, swollen at leaf nodes, and covered with coarse, downward-pointing hairs intermixed with shorter glandular hairs. It is native to Europe.

Foliage
The opposite leaves are from 1-5 in (2.5-12.7) long. They are simple, short-petioled, ovate-lanceolate to lanceolate, and sparsely pubescent on both sides.

Flowers
The flowers are borne in terminal clusters or axillary clusters. They can vary in color from purple to pink to white, are 0.5-0.75 in (1.3-1.9 cm) long, and bilaterally symmetrical.

Fruit
The egg-shaped seeds are mottled and grayish brown.

Ecological Threat
G. tetrahit invades roadsides, open woods, pastures, and fields. It can create monocultures, especially in disturbed areas. It is avoided by most grazers and is considered an agricultural weed. G. tetrahit is the host for potato fungus and several nematodes.

Selected Images

Maps

Invasive Listing Sources

• Alaska Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References