Senecio vulgaris, 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 : 204

65. S. vulgaris L. , Sp. Pl. 867 (1753).

Subglabrous or somewhat fioccose, rather succulent annual up to 40 cm, with weak, irregularly-branched stems. Leaves coarsely pinnatifid with distant, obtuse, toothed lobes; basal and lower cauline leaves oblanceolate in outline, shortly petiolate; middle and upper cauline leaves oblong in outline, auriculate-amplexicaul. Capitula numerous, 4-5 mm in diameter (in commondiscoid variant), subsessile in dense, subcorymbose clusters at anthesis; peduncles elongating in fruit. Involucre cylindrical; involucral bracts 5-8 mm, usually glabrous and often black-tipped; supplementary bracts 8-10, 1-2 mm, usually black-tipped, sometimes blackish throughout. Ligules usually absent, sometimes 6-12, yellow, short, revolute immediately after anthesis. Achenes l-5-2(-2-5) mm, appressed-hairy between the ribs. 2/7 = 40. Cultivated ground, waste places and maritime sands. Throughout Europe, but only as a casual in the extreme north. All except Sb.

Very variable in habit, leaf-shape and hairiness. Populations with ligulate capitula ( subsp. denticulatus (O. F. Mueller) P. D. Sell , Watsonia 6: 303 (1967)) have a mainly coastal distribution in W. Europe and may be native. Ligulate variants are rare inland, except in Britain, where recent experimental evidence suggests that they may arise by introgressive hybridization with 48.

In coastal parts of the Mediterranean region plants occur which are somewhat intermediate between 65 and 59. Such plants may be of hybrid origin, but experimental evidence is lacking.

S. dubius Ledeb. , FI. Alt. 4: 112 (1833), an Asiatic species recorded from S.E. Russia (Kamyšin), differs from 65 mainly in the smaller size of all its parts and its usually unlobed leaves. It has often been treated as conspecific with 65.