Parthenium
(an ancient Greek name used by Hippocrates for an allied plant, from parthenos, virgin). SYNS. Argyrochaeta, Villanova. ORD. Compositae. A genus comprising about half-a-dozen species of erect herbs, sub-shrubs, or shrubs, natives of North and Central America, and the West Indies. Flower-heads white or yellowish, heterogamous, small, disposed in terminal, sometimes densely corymbose, sometimes loose panicles; achenes glabrous or slightly pilose; involucre broadly campanulate or hemispherical; receptacle small, convex or conical. Leaves alternate, entire, toothed, or pinnately dissected, often scabrous above, more or less canotomentose or slightly glabrous below. P. Hysterophorus, the only species calling for mention in this work, is a plant of no particular beauty. It thrives in any common soil. Increased by seeds, sown in bottom heat, in spring; the seedlings should be afterwards hardened off, and transplanted in a warm, sunny spot. P. Hysterophorus (Hysterophorus). Bastard Feverfew; West Indian Mugwort. fl.-heads whitish, disposed in spreading panicles; pappus scales oblong, blunt; involucral scales acute. l. twice pinnatipartite, the uppermost ones entire. A tall, greenhouse or half-hardy, hispidulous annual. (B. M. 2275.)