Grindelia squarrosa, (Pursh) Dunal

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 : 109

1. G. squarrosa (Pursh) Dunal , Mém. Mus. Hist. Nat. (Paris) 5: 50 (1819).

Erect biennial or perennial up to 100 cm, often branched above. Leaves 3-7 cm, ovate-oblong, amplexicaul, resinous-punctate, serrate-crenate or entire. Capitula several, 2-3 cm in diameter, terminating leafy branches. Involucral bracts 3-8 x 0-5-1 mm, with cylindrical, squarrose-deflexed apex, very viscid. Ligules numerous, 7-15 mm, yellow, rarely absent. Inner florets yellow. Achenes 2-3 mm, oblong, brown. Pappus- awns 2-8, 3-5 mm, usually finely serrulate. Formerly cultivated as a medicinal plant, and naturalized in waste places in Ukraine. [Rs (W, E).] (North America)