Pieris hieracioides subsp. spinulosa

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 : 317

(c) Subsp. spinulosa (Bertol. ex Guss.) Arcangeli, Comp. FI. Ital. 418 (1882):

Capitula crowded at apex of stems on very short peduncles, the lateral capitula often sessile or nearly so. Involucre 9-11 mm, greenish, glabrous or sometimes with a few pale, rigid hairs mainly on the median line of each bract. 5. & S.C. Europe.