Scorzonera

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 : 319

Sect. Scorzonera . Leaves entire to dentate. Achenes glabrous (rarely spinulose), with smooth to lamellate ribs, without or with a short tubular base not more than | as long as the rest of the achene.