Erigeron annuus subsp. annuus

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 : 117

(a) Subsp. annuus :

Middle and lower cauline leaves strongly dentate. Stem, except for the panicle, with long, sparse, patent hairs. Ligules c. 8 mm, pale blue, rarely white.