止痢蚤草 zhi li zao cao

Inula dysenterica Linnaeus, Sp. Pl. 2: 882. 1753; Aster dysentericus Scopoli; Diplopappus dysentericus Bluff & Fingerhuth.

Herbs, perennial. Stems 20-60 cm tall, branched, lanate-tomentose and sparsely glandular, in lower part less densely pubescent. Leaves sessile, soft, 1.7-6 × 0.7-2.3 cm, most lower leaves oblong or oblanceolate, narrowed to base, other cauline leaves lanceolate, with auriculate profoundly cordate and slightly amplexicaul base, thinly gray tomentose or sublanate abaxially, green and scabrid adaxially, with short sessile fine tuberculate hairs, rarely subglabrous, margin almost entire or slightly undulate. Capitula 3-15(-20) per plant, in loose, corymbiform or racemose synflorescences, on rather long lanate tomentose peduncles, 2-6 mm. Involucre semiglobose, 1.1-1.5 cm in diam.; phyllaries numerous, in 5 or 6 series, linear, long and tapered-acuminate at apex, almost filiform, sometimes, mostly outer ones, hamate-unbent, tomentose-pilose and not densely dotted granulate-glandular outside, sparsely pilose or subglabrous inside. Ray florets ca. 2 × as long as involucre and almost 3 × as long as tubular disk florets; corolla 8-11 mm, sparsely glandular outside, mainly in upper part; lamina unbent, 1-1.3 mm wide, longitudinally 4-veined. Disk florets tubular, 3.5-4.5 mm. Achenes oblong, 1.25-1.5 × 0.3-0.4 mm, slightly compressed, longitudinally costate, ribs in upper half covered with short bristly hairs. Inner row of pappus consisting of 15-22 denticulate-scabrid hairs, 3-4.3 mm; outer row coroniform, ca. 0.25 mm. Fl. Jun-Sep. 2n = 18.

Introduced in China [native to N Africa, SW Asia, Europe, India, Nepal, and Pakistan].