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.