Vincetoxicum hirundinaria subsp. birundinaria

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 : 73

(i) Subsp. birundinaria :

Stems up to 120 cm, subglabrous or pubescent. Leaves ovate, shortly acuminate. Corolla 5-10 mm in diameter, white; lobes glabrous or hairy on upper surface. Corona-membrane more or less toothed, c. | as long as the segments; margin abruptly lobed. Throughout the range of the species, except the Iberian peninsula.