红花除虫菊 hong hua chu chong ju

Chrysanthemum coccineum Willdenow, Sp. Pl. 3: 2144. 1803; C. marschallii Ascherson; Pyrethrum coccineum (Willdenow) Voroschilov.

Herbs, perennial; stems 25-50 cm tall, erect, solitary, unbranched or few branched from base, subglabrous. Basal leaves: petiole 2-10 cm; leaf blade ovate or narrowly elliptic, 4-8 × 2.5-4 cm, 2-pinnatisect, both surfaces sparsely pubescent or glabrous; primary lateral segments 5-paired; ultimate segments triangular, elliptic, or narrowly elliptic. Stem leaves similar, sessile or shortly petiolate; leaves below capitula small, pinnatifid or entire. Capitula solitary, terminal. Involucre cup-shaped, 1-1.5 cm in diam.; phyllaries in 4 rows, scarious margin brown, outer phyllaries lanceolate, ca. 3.5 mm, abaxially glabrous or sparsely pubescent, middle and inner ones narrowly elliptic or linear-oblanceolate, ca. 5 mm, abaxially glabrous. Ray florets red; lamina narrowly elliptic, ca. 1.6 cm, apex 2- or 3-denticulate. Achenes ca. 2.5 mm. Corona 0.1-0.2 mm, margin shallowly obtusely lobed. Fl. and fr. May-Oct. 2n = 36.

Cultivated. Anhui, Hebei [native to SW Asia (Caucasus)].

Tanacetum coccineum is used as an insecticide in the same way as T. cinerariifolium and is also grown as an ornamental.