A low, upright perennial herb with erect stems. Flowers green, with the configuration typical of the spurge family (see below). Blooms April–June. Lowest leaves (on the stem beneath the flowering stems) alternate, sessile, short, and rounded. Leaves in the inflorescence branches rather large, opposite or whorled, and broadly triangular, oval, or kidney-shaped, nearly joined. Both leaf types yellow-green.
Similar species: Missouri has 20 species of Euphorbia. They all have a milky, acrid sap that is toxic to animals and can cause rashes in people. Their unusual, characteristic flowers consist of a cup (cyathium) in which a number of staminate flowers, consisting of a single stamen each, are inserted. The single female flower is a three-parted ovary on a stem that grows out of the cup after fertilization has occurred. The clusters of cyathia and nearby bracts are relatively showy and take the place of petals and sepals of normal flowers.
Height: 4 to 16 inches.
Scattered in the Ozark and Ozark Border divisions; mainly found in our central and eastern counties. Several closely related species are found statewide.
Habitat and Conservation
Occurs in bottomland forests, rich to dry upland forests, bases and ledges of bluffs, banks of streams and rivers, edges of glades, and rarely edges of fens.
Status
Globally, there are about 2,000 species in the genus Euphorbia. This genus gives its name to the entire spurge family, the Euphorbiaceae. Euphorbs are also called spurges. The milky sap in euphorbs causes a skin rash in some people, and it can cause extremely painful inflammation if it comes in contact with mucous membranes. After handling these plants (several are common houseplants) wash your hands so you don’t accidentally rub your eyes, nose, or mouth with sappy fingers.
Human Connections
Several euphorbs are important in horticulture: poinsettias and snow on the mountain, for example, and several cactuslike desert-adapted plants such as crown of thorns, candelabra tree, and pencil tree. Because of the toxic sap, don’t let small children and pets play with or chew on them.
Ecosystem Connections
The toxic, milky fluid deters herbivores, including mammals such as deer and insects such as butterfly and moth larvae and leaf-chewing beetles. Indeed, researchers describe the latex as “larvicidal.” The cyathia, however, have nectar glands that reward insect pollinators for their services.
