Herbs, annual or perennial with white latex; roots simple or with stout rootstock;
stems erect, glabrous or sparsely hairy or even glandular hairy, somewhat angular and
sometimes finely grooved. Leaves radical as well as cauline, very variable in shape, size
and lobation; radical lanceolate or ovate-oblanceolate; cauline often with rounded, toothed
auricles, stem-clasping, entire or spinous toothed, pinnatifid or runcinate-pinnatifid.
Heads broadly campanulate, glabrous or sparsely hairy or even pilose glandular hairy,
sometimes with white tomentum; peduncle slender, glabrous or hispid or glandular hairy.
Involucral bracts usually in many series, herbaceous; outermost lanceolate, oblong-oblanceolate; inner oblong or oblanceolate or linear-oblanceolate. Florets all ligulate;
corol1a yel1ow. Stamens 5, appendaged. Style slender; stigma bifid. Achenes
ovoid, oblong or oblanceolate, ellipsoid, ribbed, without beak, muricate between the
ribs, smooth or rugose. Pappus white bristly or bright, few to many seriate, simple.
Cosmopolitan weedy genus; ca 50 species. 5 in India.
Literature.
BOULOS, L. (1960). Cytotaxonomic studies in the Genus Sonchus. Bot. Not. 113: 400-
420. BOULOS, L. (1972). Revilion systematique du Genere Sonchus L.S.I. 1. Introduction et classification.
Bot. Not. 125: 287-305. BOULOS, L. (1973). Revison systematique du Genere Sonchus L.S.I. IV. Sous-genere 1- Sonchus. Bot. Not. 126: 155-196.
KEY TO THE SPECIES
1a. Basal leaves in spirals; pappus hairs heteromorphous