Annual, 1-4 dm, usually with numerous alternate branches; cauline lvs oblanceolate, 1-2 cm, acute, caducous; lvs subtending the umbel similar; lvs of the umbel round-ovate or reniform, 5-10 mm, conspicuously mucronate; rays of the umbel commonly 3, each repeatedly dichotomous; seeds brown beneath a gray coating, deeply sculptured on both sides with several transverse furrows; 2n=16. Native of the Mediterranean region, becoming established in waste places and along roads from Pa. and O. to Va. and W.Va. July-Sept. (Tithymalus f.)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.