Calystegia sepium subsp. americana, (Sims) Brummitt

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 : 78

(c) Subsp. americana (Sims) Brummitt , Ann. Missouri Bot. Gard. 52: 216 (1965):

Stems, petioles and peduncles usually pubescent. Lamina often pubescent; sinus acute. Bracteoles usually 10-20 mm wide. Corolla usually 45-65 mm, pink. Stamens 25-34 mm; anthers 4-6 mm. Salt-marshes and maritime sands. Açores. (Atlantic coasts o f North and South America.)