26. S. Boòttii, Hook. Smooth, or scabrous-pubescent or below hirsute, slender, often branched, 2–5° high; leaves rather finely serrate, ovate to oblong-lanceolate, pointed; the upper small, oblong to narrowly lanceolate, often entire; heads loosely racemose; rays 1–5 or none; achenes pubescent.—Dry grounds, Va. and southward.
27. S. argùta, Ait. Smooth; stem angled; leaves (large and thin) ovate, and the upper elliptical-lanceolate, very sharply and strongly serrate (entire only on the branches), pointed at both ends, the lowest on margined petioles; racemes pubescent, spreading, disposed in an elongated open panicle; rays 6–7, large; achenes usually glabrous. (S. Muhlenbergii, Torr. & Gray.)—Copses and moist woods, N. H. to Penn., Ont., and N. E. Minn.—Racemes much shorter and looser than in the next; the involucral scales thin and more slender; the heads somewhat larger, fully 3´´ long.
28. S. júncea, Ait. Smooth throughout (1–3° high); radical and lower stem-leaves elliptical or lanceolate-oval, sharply serrate with spreading teeth, pointed, tapering into winged and ciliate petioles; the others lanceolate or narrowly oblong, slightly triple-nerved, tapering to each end, the uppermost entire; racemes dense, naked, at length elongated and recurved, forming a crowded and flat corymb-like panicle; rays 8–12, small. (S. arguta, Torr. & Gray.)—Var. scabrélla, Gray, is somewhat roughish-pubescent (Wisc. to Ky.).—Copses and banks; common. Well distinguished by its long or drooping racemes, and the closely appressed rigid scales of the involucre, small rays, etc. Heads seldom over 2´´ long, the scales small and pale.
[++][++] Leaves more or less plainly 3-ribbed; heads in one-sided spreading or recurved racemes, forming an ample panicle. Not maritime.
[=] Smooth and glabrous, at least the stem and bright green leaves.
a. Leaves firm and rather rigid; involucral scales thickish, obtuse, quite unequal.
29. S. Missouriénsis, Nutt. Smooth throughout (1–3° high); leaves linear-lanceolate, or the lower broadly lanceolate, tapering to both ends, with very rough margins; teeth, if any, sharp and rigid; heads and dense crowded racemes nearly as in n. 28; achenes nearly glabrous.—Dry prairies, from Wisc. and Ind. south and westward.—Heads 1½–2´´ long.
30. S. Shórtii, Torr. & Gray. Stem slender, simple (2–4° high), minutely roughish-pubescent above; leaves (the larger 2–3´ long) oblong-lanceolate, acute, the lower mostly serrate with a few fine teeth; racemes mostly short in a crowded panicle; achenes silky-pubescent.—Rocks at the Falls of the Ohio; Ark.—A handsome species; heads 3´´ long, narrow.
b. Leaves thinner; involucral scales thin, chiefly linear, obtuse.
31. S. serótina, Ait. Stem stout (2–7° high), smooth, often glaucous; leaves quite smooth both sides, lanceolate, taper-pointed, very sharply serrate, except the narrowed base, rough-ciliate; the ample panicle pubescent; rays 7–14, rather long. (S. gigantea, of previous ed.)—Copses and fence-rows; common, and presenting many varieties. Seldom very tall.