Stem. - Two or three feet high. Leaves. - Ovate, lance-shaped or linear. Flowers. - Clustered within the usually five-lobed, cup-shaped involucre which was formerly considered the flower itself; the male flowers numerous and lining its base, consisting each of a single stamen; the female flower solitary in the middle of the involucre, consisting of a three-lobed ovary with three styles, each style being two-cleft. Pod. - On a slender stalk, smooth.
In this plant the showy white appendages of the cup-shaped clustered involucres are usually taken for the petals of the flower; only the botanist suspecting that the minute organs within these involucres really form a cluster of separate flowers of different sexes. While the most northerly range in the Eastern States of this spurge is usually considered to be New York, the botany states that it has been recently naturalized in Massachusetts. It blossoms from July till October.