Description from Flora of China
Conyza cinerea Linnaeus, Sp. Pl. 2: 862. 1753; Blumea chinensis (Linnaeus) Candolle (1836), not Walpers (1843), nor Hooker & Arnott (1837); B. esquirolii H. Léveillé & Vaniot; Cacalia cinerea (Linnaeus) Kuntze; Conyza chinensis Linnaeus; Cyanthillium cinereum (Linnaeus) H. Robinson; Seneciodes cinerea (Linnaeus) Kuntze; Serratula cinerea (Linnaeus) Roxburgh; Vernonia abbreviata Candolle; V. cinerea var. parviflora (Reinwardt) Candolle; V. exilis Miquel; V. parviflora Reinwardt ex Blume.
Herbs, annual or perennial, to 100 cm tall. Root vertical, ± woody, branched, with fibrous rootlets. Stems erect, usually branched above, or rarely from base, striate, gray adpressed puberulent with T-shaped hairs, glandular. Lower and middle leaves: petiole 10-20 mm, leaf blade rhombic-ovate, rhombic-oblong, or ovate, 3-6.5 × 1.5-3 cm, abaxially gray-white or yellowish puberulent, especially along veins, both surfaces glandular, adaxially green, sparsely puberulent, lateral veins 3- or 4-paired, base cuneately attenuate into winged petiole, margin remotely mucronate-serrate, or repand, apex acute or slightly obtuse; upper leaves progressively smaller, shortly petiolate or subsessile, narrowly oblong-lanceolate or linear. Synflorescences terminal, flat-topped, panicles branching often rather divaricate. Capitula many, rarely few, 6-8 mm in diam.; peduncle 5-15 mm; bracteoles linear, sometimes absent, densely puberulent. Involucre campanulate, 4-5 × 6-8 mm; phyllaries 4-seriate, green or sometimes becoming purple, outer linear, 1.5-2 mm, puberulent and glandular, apex acuminate, median linear, inner linear-lanceolate, spinescent, 1-veined or sometimes conspicuously 3-veined in upper part. Receptacle flat, foveolate. Florets 19-28; corolla reddish purple, tubular, 5-6 mm, sparsely puberulent, glandular; lobes linear-lanceolate, puberulent and glandular at apex. Achenes cylindric, ca. 2 mm, densely puberulent and glandular. Pappus 2-seriate, white; outer setae many, short; inner setae 4-5 mm, scabrid. Fl. year-round. 2n = 18.
Vernonia cinerea is used medicinally for a variety of purposes, including to reduce fever, draw out pus, promote digestion, relieve dyspepsia, and as a tranquilizer and sedative.
Dwarf plants, usually less than 20 cm tall, with smaller capitula and more sparsely hairy leaves are sometimes placed in Vernonia cinerea var. parviflora (Reinwardt) Candolle (Prodr. 5: 24. 1836; 小花夜香牛 xiao hua ye xiang niu).
Weed of open disturbed sites. Fujian, Guangdong, Guangxi, Hubei, Hunan, Jiangxi, Sichuan, Taiwan, Yunnan, Zhejiang [India, Indonesia, Japan, Malaysia, Myanmar, Papua New Guinea, Philippines, Sri Lanka, Thailand, Vietnam; Africa, Arabia, Australia, Pacific islands; introduced to the Americas].