Cypress spurge is a low-growing perennial that overwinters as root and crown tissue. Cypress spurge reproduces by seed and lateral root buds. Leaves are linear, approximately 1/2 to 1 1/4 inches long, and 1 to 2 mm wide. Upper stem leaves that occur near the inflorescence are yellow or yellowish-green in color. Leaves are stalkless, alternate, narrow, and linear to lance-shaped. Stems are 4 to 32 inches high, hairless, green to yellowish-green in color, and branch in the upper portions. The leaves and stems emit a milky, toxic sap when broken. Flowers are yellowish-green usually turning reddish-green towards maturity and are clustered in bunches at the ends of stems.