* Hay-florets small, revolute.
S. sylvaticus: annual; stems 1-2 feet high, erect, branched, downy; leaves deeply pinnatifid, downy with oblong unequally-toothed segments; flower-heads numerous, in a loose corymb; the outer florets ligulate, but small and rolled back. - Banks, waste places, and borders of woods. Fl. July to August.
S. viscosus resembles this, but is coarser, and covered with a short, viscous, strong-smelling down.
** Hay-florets spreading, conspicuous.
S. Jacobsea: stems 2-4 feet high, erect, scarcely branched, except at top; lower leaves oblong-ovate, lyrate pinnatifid, those of the stem sessile, bipinnatifid, with oblong deeply-toothed segments; flower-heads rather large, bright yellow, in a compact terminal corymb; involucral bracts tipped with black; ray-florets 12-15, linear-oblong; achenes of the disk covered with short hairs, those of the ray glabrous. - Ragwort. - Roadsides, waste places, and bushy pastures. Fl. July to September. It sometimes assumes the spreading inflorescence of S. aquaticus, in which the achenes both of the disk and ray are however always smooth.
S. erucaefolius resembles this, but the leaves are more regularly divided into narrower segments, the terminal ones not very different from the others; and the achenes of the ray-florets are hairy like those of the disk. [See also p. 58.]