Aster pilosus, Willd.

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 : 114

11. A. pilosus Willd. , Sp. Pl. 3: 2025 (1803).

Perennial 30-60 cm. Stem erect or oblique, branched from near the base, glabrous to densely hirsute. Leaves linear to linear-lanceolate, the lowest petiolate and sometimes lanceolate, glabrous to hirsute, not auriculate at base, entire or obscurely toothed. Capitula in a wide panicle, on long peduncles with linear leaves, sometimes arranged unilaterally along the branches. Involucral bracts in several rows, acute, the largest 4-5-7 mm, the outer shorter than the inner, lax, with a subulate, green apex inrolled at the margin. Ligules white, often becoming purplish, c. 1 -5 mm wide. Locally naturalized. [Ho Hs It.] (North America.)

This has often been mistaken for A. ericoides L. , Sp. Pl. 875 (1753), which is similar in habit but has smaller, more oblong leaves in the inflorescence, the longest involucral bracts only 3-5 mm and the outer involucral bracts spinulose-mucronate and recurved. A native of North America, it is probably nowhere established in Europe.