Rhaponticum
(from Rha, the old Greek name for Rhubarb, and Ponticus, of Pontus. It was also called Rheum barbarum. See Rheum). ORD. Compositae. A genus comprising about half-a-dozen species of annual or perennial herbs, of which the best known is described below. Rhaponticum is included, by Bentham and Hooker, under Centaurea (which see for culture). R. scariosum (scarious). fl.-heads purple; outer involucral scales all scarious, sub-entire or at length cut; inner ones narrower and very acuminate. July l. glabrous above, canotomentose beneath; lower ones petiolate, ovate or cordate, denticulate; middle ones shortly petiolate, ovate-oblong; uppermost ones sessile, oblong, acuminate at both ends, scarcely toothed. h. 2 1/2ft. Switzerland, &c., 1640. (B. M. 1752, under name of Centaurea Rhapontica.)