苏门白酒草 su men bai jiu cao

Conyza sumatrensis (Retzius) E. Walker.

Herbs, annual or biennial, 80-150 cm tall; roots fusiform. Stems erect, thick, branched above middle, densely leafy, densely gray-white strigose, sparsely hirsute. Leaves: basal withered at anthesis, lower cauline petiolate, blade oblanceolate or lanceolate, 6-10 × 1-3 cm, surfaces densely strigose, especially abaxially, base attenuate, margin usually coarsely 4-8-serrate per side, apex acute or acuminate, mid and upper reduced, blade narrowly lanceolate to linear, margin serrate or entire. Capitula 5-8 mm in diam., numerous, in large and long paniculiform synflorescences; peduncles 3-5 mm. Involucre campanulate to urceolate, ca. 4 × 3-4 mm; phyllaries 3-seriate, gray-green, linear-lanceolate or linear, abaxially scabrous, apex acuminate, outer short or ca. 1/2 as long as inner, inner ca. 4 mm, margin scarious. Ray florets numerous, 4-4.5 mm, lamina yellowish or purplish, short, filiform, apex 2-denticulate; disk florets 6-11, yellowish, ca. 4 mm, tube sparsely puberulent. Achenes linear-lanceoloid, compressed, 1.2-1.5 mm, strigillose. Pappus white, later yellowish brown. Fl. May-Oct.

Common weed of grasslands on slopes, open places, roadsides, streamsides; 100-2500 m. Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hunan, Jiangsu, Jiangxi, Sichuan, Taiwan, Xizang, Yunnan, Zhejiang [presumably native to South America; widely distributed as a weed in tropical and subtropical regions worldwide].