Senecio squalidus, 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 : 202

48. S. squalidus L. , Sp. Pl. 869 (1753)

( S. nebrodensis auct., non L.).

Subglabrous to more or less fioccose short-lived perennial, biennial or annual up to 60 cm, with erect, branching stems. Leaves glabrescent above, the lower usually deeply pinnatifid with rather distant lobes, attenuate into a winged petiole, the upper cauline more or less pinnatifid, auriculate-amplexicaul (more rarely all leaves merely dentate.) Capitula 15-25 mm in diameter, few to numerous in a lax, irregular corymb. Involucral bracts c. 20, 7-10 mm; supplementary bracts 5-13, 2-3 mm; all lanceolate, black-tipped. Ligules c. 13,10-12 mm, bright yellow. Achenes 2-3 mm, usually hairy. 2л = 20. Woodland and scrub, and also on disturbed rocky ground, especially in the northern part of the range. • C. & S. Europe, mainly in the mountains; abundantly naturalized in Britain and locally elsewhere in N. & C. Europe. Al Au Bu Cr Cz Ge Gr He It Ju Rm Sa Si [Br Da Ga Hb Hu].

The plant naturalized in Britain is very variable in leaf-shape, but the native plant of C. Europe (which was described as S. rupestris Waldst. & Kit. , Pl. Rar. Hung. 2: 136 (1803)) is much less variable. Variants indistinguishable from typical S. rupestris are often found in Britain, and the plants are completely interfertile. The species was described from Oxford, where it was already naturalized on old walls in the seventeenth century.

S. fruticulosus Sibth. & Sm. , FZ. Graec. Prodr. 2: 178 (1813), from mountains in Kriti, is a rather dwarf, glabrous perennial with a woody stock, differing from small variants of 48 mainly in its undivided, remotely dentate leaves. It may merit subspecific rank.