Autik. Bot., 158. 1840.
Introduced; B.C., Ont., Que., Alaska, Calif., Conn., Fla., Idaho, Ill., Ky., Maine, Mich., N.J., N.Y., Ohio, Oreg., Pa., Utah, Va., Wash., Europe, sw, sc Asia, n Africa, introduced also in South America, s Africa, Pacific Islands, Australia.
Subspecies 2 (1 in the flora).
Subspecies gibbosum (Wallich) D. A. Sutton, which occurs in the eastern Mediterranean, southwestern and south-central Asia, and northeastern Africa, has more slender stems, smaller flowers, and more lax inflorescences than subsp. orontium (D. A. Sutton 1988). Subspecies gibbosum does not appear to have been introduced in the flora area.