Galium album subsp. pycnotrichum

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 : 24

(b) Subsp. pycnotrichum (H. Braun) Krendl, Österr. Bot. Zeitschr. 114: 539 (1967):

Stems up to 150 cm, robust, usually hairy, erect, the branches short. Leaves 10-40 x 2-7 mm, oblong to broadly oblanceolate, abruptly narrowed towards apex. Inflorescence usually broadly ovoid. Corolla whitish. 2л = 44. E.C. & S.E. Europe.