Vincetoxicum hirundinaria subsp. nivale, (Boiss. & Heldr.) Markgraf

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 72

(c) Subsp. nivale (Boiss. & Heldr.) Markgraf , op. cit. 375 (1971)

( Vincetoxicum nivale Boiss. & Heldr. ; inch Cynanchum sulfureum (Velen.) Hayek , C. vincetoxicum var. nivale (Boiss. & Heldr.) Hayek):

Stems 20-30 cm, minutely pubescent. Leaves broadly ovate, acute. Corolla 8-9 mm in diameter, yellow; lobes glabrous on upper surface. Corona-membrane c. £ as long as the segments, more or less folded or toothed. • Balkan peninsula.