Description from Flora of China
Thorelia Gagnepain (1920), nom. cons., not Hance (1877); Thoreliella C. Y. Wu.
Herbs, annual; indumentum of simple hairs and sessile globose glands. Leaves alternate, petiolate, margin repand or serrate, pinnately veined. Synflorescence terminal, paniculate, often reduced to 1 or 2 capitula. Involucre hemispheric; phyllaries to 6-seriate, imbricate, herbaceous, with marginal setae. Receptacle flat, rounded foveolate, naked. Florets many; corolla purple or purplish, tubular, slender, with narrowly campanulate limb; lobes 5, triangular or linear-lanceolate, often glandular hairy. Anthers obtusely auriculate at base. Style branches linear, acuminate, puberulent. Achenes obovate or oblong-obovoid, rather compressed, 10-ribbed or rarely 5-ribbed, glabrous though sometimes glandular between ribs. Pappus sparse or absent, bristles 1-10, scabrid, easily deciduous.
Species have been transferred recently to Vernonia and Iodocephalopsis S. Bunwong & H. Robinson.
Five species: China, Laos, Thailand, Vietnam; one species in China.