Solidago canadensis, L.

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 : 110

3. S. canadensis L. , Sp. Pl. 878 (1753).

Rhizomatous. Stems 30-150 cm, glabrous at the base, pubescent or scabrid at least in the upper |, with 40-110 leaves scarcely decreasing in size upwards. Leaves lanceolate, long-attenuate, pubescent or scabrid on the margin and veins beneath or occasionally throughout, sharply serrate, with 2 prominent lateral veins; basal soon deciduous; middle cauline 6-13 x 0-5-1-8 cm. Panicle broadly pyramidal, the branches patent, with strongly secund capitula. Involucre 2-2-8 mm. Ligules 10-17, 1-1-5 mm. Tubular florets usually fewer than the ligules; corolla 2-4-2-8 mm. Achenes 0-9-1-2 mm, shortly pubescent; pappus 2-2-5 mm. Cultivated for ornament and widely naturalized in Europe. [Au Be Br?Bu Cz Da Ga Ge Hb He Ho Hs Hu No Po Rm Rs (B, C, W).] (North America.)

The plants naturalized in Europe all appear to be referable to var. canadensis', the very similar S. altissima L. , Sp. Pl. 878 (1753) ( S. canadensis var. scabra Torrey & A. Gray ) is cultivated and may also be naturalized. It is 70-200 cm, has more hairy leaves and stem, and larger capitula with involucre 3-2-5 mm and corolla of tubular florets 3-4 mm.