1. E. Canadénsis, L. (Horse-weed. Butter-weed.) Bristly-hairy; stem erect, wand-like (1–5° high); leaves linear, mostly entire, the radical cut-lobed; heads very numerous and small, cylindrical, panicled.—Waste places; a common weed, now widely diffused over the world. July–Oct.—Ligule of the ray-flowers much shorter than the tube, white.
2. E. divaricàtus, Michx. Diffuse and decumbent (3´–1° high); leaves linear or awl-shaped, entire; heads loosely corymbed; rays purple; otherwise like n. 1.—Ind. to Minn., and southward.
§ 2. TRIMORPHÆ̀A. Like § 1, but a series of filiform rayless pistillate flowers within the outer row of ray-flowers; biennial or sometimes perennial.
3. E. àcris, L. Hirsute-pubescent or smoothish; stem erect (10–20´ high); leaves lanceolate or the lower spatulate-oblong, entire; heads several or rather numerous, racemose or at length corymbose, nearly hemispherical (4–5´´ long), hirsute; rays purplish or bluish, equalling or a little exceeding the copious pappus.—Lower St. Lawrence, across the continent and northward. The var. Drœbachénsis, Blytt, more glabrous and with the green involucre nearly or quite naked, occurs on the shores of L. Superior. (Eu.)
§ 3. ERIGERON proper. Rays elongated (short in a form of n. 5), crowded in one or more rows.
[*] Annuals (or sometimes biennial), leafy-stemmed and branching; pappus double, the outer a crown of minute scales, the inner of deciduous fragile bristles, usually wanting in the ray.
4. E. ánnuus, Pers. (Daisy Fleabane. Sweet Scabious.) Stem stout (3–5° high), branched, beset with spreading hairs; leaves coarsely and sharply toothed; the lowest ovate, tapering into a margined petiole, the upper ovate-lanceolate, acute and entire at both ends; heads corymbed; rays white, tinged with purple, not twice the length of the bristly involucre.—Fields and waste places; a very common weed. June–Aug. (Nat. in Eu.)
5. E. strigòsus, Muhl. (Daisy Fleabane.) Stem panicled-corymbose at the summit, roughish like the leaves with minute appressed hairs, or almost smooth; leaves entire or nearly so, the upper lanceolate, scattered, the lowest oblong or spatulate, tapering into a slender petiole; rays white, twice the length of the minutely hairy involucre.—Fields, etc., common. June–Aug.—Stem smaller and more simple than the last, with smaller heads but longer rays. A form with the rays minute, scarcely exceeding the involucre, occurs in S. New England.
[*][*] Leafy-stemmed perennials; pappus simple (double in n. 6).
6. E. glabéllus, Nutt. Stem (6–15´ high) stout, hairy above, the leafless summit bearing 1–7 large heads; leaves nearly glabrous, except the margins, entire, the upper oblong-lanceolate and pointed, closely sessile or partly clasping, the lower spatulate and petioled; rays (more than 100, purple) more than twice the length of the hoary-hispid involucre; pappus double, the outer of minute bristles.—Plains of N. Wisc., and westward. June.