[*][*] Involucral scales without green tips and wholly appressed.
[+] Heads small (3´´ long), clustered along the stem in the axils of the feather-veined leaves, or the upper forming a thyrse.
[++] Achenes pubescent.
3. S. cæ̀sia, L. Smooth; stem terete, mostly glaucous, at length much branched and diffuse; leaves lanceolate or oblong-lanceolate, serrate, pointed, sessile; heads in very short clusters, or somewhat racemose-panicled on the branches.—Rich woodlands, common; west to S. E. Minn., Ill., and Ky.
4. S. latifòlia, L. Smooth or nearly so; stem angled, zigzag, simple or paniculate-branched (1–3° high); leaves broadly ovate or oval, very strongly and sharply serrate, conspicuously pointed at both ends (thin, 3–6´ long); heads in very short axillary clusters, or the clusters somewhat prolonged at the end of the branches; rays 3–4.—Moist shaded banks; common northward, and south along the mountains.
5. S. Curtísii, Torr. & Gray. Smooth or nearly so; stem angled, usually branched; leaves oblong to long-lanceolate with narrowed entire base, serrate above with subulate teeth; heads in small, loose clusters; rays 4–7.—Open woods at low elevations in the mountains of Va. and southward.
[++][++] Achenes glabrous; inflorescence more thyrsoid.
6. S. bícolor, L. Hoary or grayish with soft hairs; stem mostly simple; leaves oblong or elliptical-lanceolate, acute at both ends, or the lower oval and tapering into a petiole, slightly serrate; clusters or short racemes from the axils of the upper leaves, forming an interrupted spike or crowded panicle; scales very obtuse; rays (5–14) small, cream-color or nearly white.—Var. cóncolor, Torr. & Gray, has the rays yellow.—Dry copses, west to Minn. and Mo.
7. S. montícola, Torr. & Gray. Nearly glabrous; stem slender, 1–2° high; leaves oblong-ovate to lanceolate, acute or tapering at both ends, the lower sparingly serrate; heads small, the scales acutish; rays 5–6.—Alleghany Mts., from Md. southward.
[+][+] Heads mostly large (smaller in n. 12), many-flowered, forming an erect terminal thyrse; leaves feather-veined.