8. A. rádula, Ait. Stem simple or corymbose at the summit, smooth or sparsely hairy, many-leaved (1–3° high); leaves oblong-lanceolate, pointed, sharply serrate in the middle, very rough both sides and rugose-veined, closely sessile (2–3´ long), nearly equal; scales of the bell-shaped involucre oblong, appressed, with very short and slightly spreading herbaceous tips; achenes smooth.—Bogs and low grounds, Del. to Maine and northward, near the coast; also Pocono Mountain, Penn. A dwarf form (var. stríctus, Gray) has oblong- to linear-lanceolate nearly entire leaves, and usually solitary heads; White Mountains, N. H., to Lab. Aug.—Rays light violet. Involucre nearly smooth, except the ciliate margins.
[*] 2. Involucre and usually the branchlets viscidly or pruinose-glandular, well imbricated or loose; pubescence not silky; leaves entire (or the lower with few teeth), the cauline all sessile or clasping; rays showy, violet to purple.
[+] Heads small; involucre not squarrose. Extreme western.
9. A. Féndleri, Gray. Rigid, 1° high or less; leaves firm, linear, 1-nerved, hispid-ciliate, 1´ long or mostly much less; heads scattered, 3´´ high; scales linear-oblong, obtuse, or the inner acute.—Central Kan. (Ellis, Dr. L. Watson) and southwestward.
[+][+] Heads larger; involucral scales spreading, in few or many ranks.
10. A. grandiflòrus, L. Rough with minute hispid hairs; stems slender, loosely much branched (1–3° high); leaves very small (¼–1´ long), oblong-linear, obtuse, rigid, the uppermost passing into scales of the hemispherical squarrose many-ranked involucre; rays bright violet (1´ long); achenes hairy.—Dry open places, Va. and southward.—Heads large and very showy.
11. A. oblongifòlius, Nutt. Minutely glandular-puberulent, much branched above, rigid, paniculate-corymbose (1–2° high); leaves narrowly oblong or lanceolate, mucronate-pointed, partly clasping, thickish (1–2´ long by 2–5´´ wide); involucral scales nearly equal, broadly linear, appressed at the base; rays violet-purple; achenes canescent.—Banks of rivers, from Penn. and Va. to Minn. and Kan.—Heads middle-sized or smaller.
Var. rigídulus, Gray. Low, with more rigid and hispidulous scabrous leaves.—In drier places, Ill., Wisc., and southwestward.
12. A. Nòvæ-Ángliæ, L. Stem stout, hairy (3–8° high), corymbed at the summit; leaves very numerous, lanceolate, entire, acute, auriculate-clasping, clothed with minute pubescence, 2–5´ long; scales nearly equal, linear-awl-shaped, loose, glandular-viscid, as well as the branchlets; rays violet-purple (in var. ròseus rose-purple), very numerous; achenes hairy.—Moist grounds; common.—Heads large. A peculiar and handsome species.
13. A. modéstus, Lindl. Pubescent or glabrate; stem slender, simple, with few large heads terminating slender branchlets; leaves lanceolate, very acute, narrowed to a sessile base, sparingly serrate or serrulate; scales linear-attenuate, equal, mostly herbaceous; rays blue.—N. Dak. and westward.