Prolongoa Boiss.

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 : 173

75. Prolongoa Boiss. 1

Annuals. Leaves alternate. Capitula solitary. Involucral bracts in 2-3 rows, the margin widely scarious. Receptacle convex, without scales. Ligulate florets sterile; inner florets hermaphrodite, actinomorphic, tubular-conical; tube slightly compressed at base, but not winged. Achenes all similar, trigonous, incurved, the outer with 2 lateral and 1 adaxial ribs, and 2 thick abaxial ribs; epicarp mucilaginous; vallecular secretory canals absent.