Marsh spurge (Euphorbia palustris) produces masses of chartreuse-yellow bracts (the actual flowers are not showy) on top of a perennial plant growing to 3 feet in height by 4 feet in width. Green willowlike leaves that spiral out from the stems turn bright orange and yellow in fall. This species tolerates moist soil, and dry soil later in the growing season. Deer find the milky sap objectionable; the sap also irritates the skin and eyes of gardeners.