Alternate name: Wolf's-milk

Family: Euphorbiaceae, Spurge view all from this family

Description Introduced; invasive. A broad, open, dome-shaped cluster of tiny, greenish flowers among broad paired bracts; stems with milky sap.
Flowers: Attached to inside of a cup about 1/8" (3 mm) wide; 4 tan-green, crescent-shaped glands perching at edge of cup; ovary spherical, smooth or warty, 3-lobed, protruding on stalk from center of cup.
Leaves: Those at midstem 3/4-2 1/2" (2-6.5 cm) long, very narrow; those in flower cluster forming paired, broadly heart-shaped bracts, each 1/2-3/4" (1.5-2 cm) long.
Fruit: Spherical capsule, about 1/8" (3 mm) wide; splitting open explosively.
Height: 8-36" (20-90 cm).

Warning Can be toxic if ingested; known to fatally poison cattle. Contact with plant, especially milky sap, can cause irritation of skin, eyes, and mucous membranes. Sensitivity to a toxin varies with a person’s age, weight, physical condition, and individual susceptibility. Children are most vulnerable because of their curiosity and small size. Toxicity can vary in a plant according to season, the plant’s different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil.

Flower May-June.

Habitat Open areas, especially where disturbed.

Range Eurasia native; introduced in North America and naturalized in southern Canada and much of United States, except southeastern quadrant from North Carolina to Florida and west to Oklahoma and Texas.

Discussion Introduced from Eurasia, Leafy Spurge is a noxious weed difficult to eradicate because of its deeply buried perennial runners. Considered one of the worst invasives in North America, it is an especial problem in the Great Plains. It emerges earlier in the spring than other plants, getting a head start and preventing seedlings of other plants from gaining a foothold. It may prevent other plants from sprouting by releasing toxins into the soil.