AppearanceEuphorbia cyparissias grows up to 12 in. (30.5 cm) tall. This herbaceous, perennial plant invades open disturbed areas throughout the United States. All parts of the plant exude a white, milky sap when broken.Foliage The leaves are small, up to 1 in. (2.5 cm) long. The leaves are numerous, alternate or whorled, bright green, and linear in shape. Flowers Yellow-green, inconspicuous flowers are in a cyme at the top of the plant. Flowers mature to red.Fruit The fruit is three lobed and contains 1-3 egg shaped smooth gray seeds that measure 0.06-0.08 in. (1.5-2 mm). Euphorbia cyparissias produces large clonal colonies through an extensive underground root system, that allows this plant to reproduce with lateral root buds.Ecological ThreatEuphorbia cyparissias can invade open disturbed areas such as fields, pastures, agricultural land, roadsides, and yards. It is toxic to livestock so infestations reduce the forage value of pastures and contaminates hayfields. It can form huge infestations displacing native vegetation. This plant is native to Europe and western Asia. It was first introduced into the United States in the mid 1800s as an ornamental.