Tetragonotheca
(from tetragonos, quadrangular, and theke, a case; alluding to the four-angled grains). ORD. Compositae. A small, North American genus (three species) of tall, erect, hardy, perennial herbs. Flower-heads yellow, rather large, solitary or loosely corymbose, heterogamous; ray florets ligulate, spreading; involucre explanate, with four bracts in one series; achenes thick, triangular, glabrous or slightly pilose. Leaves opposite, amplexicaul, deeply toothed or incised-pinnatifid. Only one species has been introduced. It is an interesting plant, thriving in any light, rich soil. Propagation may be effected by divisions, or by seeds.
T. helianthoides (Sunflower-like). fl.-heads pale yellow, large, pedunculate, terminating the branches; involucre 2in. or more in diameter. August. l. 3in. to 6in. long, repandly and unequally toothed, or with coarse, sharp, salient teeth. Stem 2ft. to 3ft. high, terete. 1726.