leafy spurge
Euphorbia esula L.

Overview

Appearance

Euphorbia esula is an erect, perennial, herbaceous plant that grows from 2-3.5 ft. (0.6-1.1 m) tall. The stem is smooth and bluish-green. The plant produces a milky sap if stem is broken or a leaf is removed.

Foliage

Leaves are lance shaped, smooth and 1-4 in. (2.5-10.2 cm) long. They are arranged alternately along the stem, becoming shorter and more ovate towards the top of the stem.

Flowers

Flowering occurs in June, when yellow flowers develop in clusters at the apex of the plant.

Fruit

Fruits are 3 lobed capsules that explode when mature, propelling brown mottled ovoid seeds up to 15 ft. (4.6 m) away.

Ecological Threat

Large infestations of Euphorbia esula give the landscape a yellowish tinge due to the yellow bracts. Leafy spurge invades prairies, pastures, and other open areas. It is a major pest of national parks and nature preserves in the western United States. It can completely overtake large areas of land and displace native vegetation. This plant is native to Europe and was introduced accidentally into North America in the early 1800s as a seed contaminate.

Resources

• Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service
• Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
• Element Stewardship Abstract - The Nature Conservancy
• Federal Noxious Weed Disseminules of the U.S. - USDA-APHIS
• Weed of the Week - USDA Forest Service
• Weed Field Guide - USDA Forest Service

Selected Images

Maps

Invasive Listing Sources

• Alaska Noxious Weeds
• Alberta Weed Control Act
• Arizona Noxious Weeds
• California Invasive Plant Council
• California Noxious Weeds
• City of Ann Arbor Michigan Parks and Recreation
• Colorado Noxious Weeds
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Connecticut Noxious Weeds
• 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.
• Idaho Noxious Weeds
• Indiana Invasive Species Council - Invasive Plant List
• Invasive Plant Association of Wisconsin
• Iowa Noxious Weeds
• Jil M. Swearingen, Survey of invasive plants occurring on National Park Service lands, 2000-2007
• John Randall, The Nature Conservancy, Survey of TNC Preserves, 1995.
• Kansas Noxious Weeds
• Kentucky Exotic Pest Plant Council - Watch List
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• Michigan Noxious Weeds
• Minnesota Noxious Weeds
• Montana Noxious Weeds
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Nebraska Noxious Weeds
• Nevada Noxious Weeds
• New Mexico Noxious Weeds
• New York Regulated and Prohibited Invasive Species - Prohibited
• Nonnative Invasive Species in Southern Forest and Grassland Ecosystems
• North Dakota Noxious Weeds
• Ohio Noxious Weeds
• Ontario’s Invading Species Awareness Program Tracked Species List
• Oregon Noxious Weeds
• Pacific Northwest Exotic Pest Plant Council, 1998
• South Dakota Noxious Weeds
• Utah Noxious Weeds - Control
• Washington Noxious Weeds
• WeedUS - Database of Plants Invading Natural Areas in the United States
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40
• Wyoming Noxious Weeds

References