Trifolium obscurum, Savi

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1981, Flora Europaea. Volume 2. Rosaceae to Umbelliferae, Cambridge University Press : 172

95. T. obscurum Savi , Obs. Trif. 31 (1810).

Annual; stems 20-60 cm, little-branched, often flexuous, glabrous below, appressed-hairy above. Leaflets 15-20 x 7-12 mm, obovate to oblong-lanceolate. Free part of the stipules lanceolate or linear, herbaceous. Heads 20-35 mm, shortly pedunculate, globose, oblong-ovoid or conical-cylindrical and rather lax in fruit. Fruiting calyx with an ovoid, glabrescent or hairy tube, usually somewhat constricted above; teeth almost equal, about as long as the tube, ovate-lanceolate, all with 3 or 5 veins, sometimes with anastomoses, herbaceous, patent. Corolla 4-5 mm, whitish or pale pink, not exceeding the calyx. Legume included. Moist, sandy fields. C. & S. Italy; S. Spain. Hs It. (N.W. Africa.)