With a natural range in Tex., is occasionally found as a roadside weed in our range, especially southward. It is a much smaller and more delicate plant than H. annuus, seldom as much as 1 m tall, and the stem is strongly mottled. (H. cucumerifolius)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.