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.