Foliage
The leaves are opposite, 6-10 in. (15-25 cm) long, velvety and lanced-shaped.

Flowers
Flowering occurs from May to August, when dense clusters of tubular flowers develop. These flowers have 4 petals and can be purple, white, or pink. The flowers produce high quantities of nectar and are attractive to butterflies, hence the common name.

Fruit
The developing pods are small upright ovate pods, which may not be readily visible through the remnants of the flower. When mature, the pods are dark brown and open at the tip. The seeds are dust-like particles that can easily be distributed by the wind.

Ecological Threat
Buddleja davidii readily invades disturbed sites and riparian areas. Although butterflies will use this plant as a nectar source their larvae cannot survive on it. By replacing native larval food source plants butterfly bush can have a negative impact on wildlife.

Citation
Rawlins, K.A., R.L. Winston, C.T. Bargeron, D.J. Moorhead, and R. Carroll. 2018. New Invaders of the Northeast and Northcentral United States. USDA Forest Service, Forest Health Assessment and Applied Sciences Team, Morgantown, West Virginia. FHTET-2017-04. Retrieved from https://bugwoodcloud.org/resource/pdf/FHTET-2017-04_New%20Invaders_NE.pdf
 

Resources

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

Selected Images

Maps

Invasive Listing Sources

• California Invasive Plant Council
• Delaware Invasive Species Council
• Delaware Invasive Species Council Invasive Species List
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• Jil Swearingen, personal communication, 2009-2017
• Kentucky Exotic Pest Plant Council - Moderate Threat
• Maine Invasive Plants
• Maryland Department of Natural Resources Policy: Restriction on Planting Exotic Invasive Plants
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• National Park Service, National Capital Region Exotic Plant Management Team Invasive Plant List
• Native Plant Society of Oregon, 2008
• New Invaders of the Northeast and Northcentral
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• Non-Native Invasive Plants of Arlington County, Virginia
• Non-Native Invasive Plants of the City of Alexandria, Virginia
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Plant Invaders of Mid-Atlantic Natural Areas
• Reichard, Sarah. 1994.  Assessing the potential of invasiveness in woody plants introduced in North America. University of Washington Ph.D. dissertation.
• South Carolina Invasive Pest Council
• Tennessee Exotic Pest Plant Council
• Virginia Invasive Plant Species List
• Virginia Master Naturalists Priority Species List
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States

References