Aetheorhiza bulbosa subsp. bulbosa

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 : 326-327

(a) Subsp. bulbosa :

Leaves usually sinuate-denticulate. Involucral bracts (13—)14—15(—16) x c. 2 mm, linear-lanceolate,

abruptly narrowed to the subobtuse apex. Achenes 3-4-5 mm. Throughout most of the range of the species.