Senecio jacobaca, L.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 201

44. S. jacobaca L. , Sp. Pl. 870 (1753).

Biennial or perennial 30-150 cm. Stock short, erect. Stems subglabrous to fioccose, branched only in inflorescence. Basal and lower cauline leaves 10-20 cm, lyrate-pinnatifid, petiolate, usually withered at anthesis; middle and upper cauline 1- to 2-pinnatifid, with segments at right angles to rhachis, semi-amplexicaul, usually sparsely fioccose beneath. Capitula 15-20 mm in diameter, numerous, in a rather dense corymb. Involucre 7-10 mm, subglabrous, with 2-5 supplementary bracts c. | as long as the narrowly ovate, acute involucral bracts. Ligules 12-15, yellow, rarely ( var. flosculosus DC. ) absent. Achenes c. 2 mm, the outer glabrous, the inner shortly hairy; pappus c. 4 mm, caducous. 2л = 40, 80. Most of Europe, but rare in the extreme south and north. Al Au Be Br Bu Co Cz Da Ga Ge Gr Hb He Ho Hs Hu It Ju Lu No Po Rm Rs (*N, B, C, W, К, E) Su [Fe]. S. borysthenicus (DC.) Stankov in Stankov & Taliev, Opred. Vysš. Rast. Evrop. SSSR 651 (1949), widespread in the C. & S. parts of the U.S.S.R., differs from 44 mainly in the 2- to 3- pinnatifid leaves, and may be worthy of subspecific rank.