This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol3", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Senecio aureus var. discoideus Hook. Fl. Bor. Am. 1:
333. 1833. Senecio discoideus Britton, in Britt. & Brown, III. Fl.
3: 479. 1898.
Perennial, glabrous except for small tufts of wool in the axils of the lower leaves; stem rather stout, 1°-2 1/2° tall; basal leaves oval to ovate, obtuse, thin, sharply dentate, abruptly narrowed into petioles longer than the blade; stem leaves few, small, more or less laciniate; heads few or several, slender-peduncled, corymbose; principal bracts of the involucre narrowly linear, 3"-S" long, the short outer ones few or none; rays none; achenes glabrous.
In moist places, Labrador to Yukon, Quebec, Michigan, Wyoming and British Columbia. June-Aug.
Senecio obovatus Muhl.; Willd. Sp. Pl. 3: 1999. 1804. Senecio Elliottii T. & G. Fl. N. A. 2: 443. 1843. S. aureus var. obovatus T. & G. loc. cit. 442. 1843. S. rotundus (Britton) Small, Fl. SE. U. S. 1304. 1903.
Perennial; stems glabrous, or a little woolly at the base, 9'-24' high. Leaves glabrous, rather thick, the basal ones obovate with a cuneate base, suborbicular or broadly spatulate, very obtuse and rounded at the apex, 1-3 1/2' long, 5-2' wide, crenate-dentate, often purplish; stem leaves commonly few and sessile, spatulate to oblong, often incised or pinnatifid; heads several, corymbose, 6"-8" broad, about 3" high, slender-peduncled; involucre nearly cylindric, its principal bracts linear-lanceolate, 2"-3" long, acute, usually with 1-3 small exterior ones; rays 8-12, usually conspicuous, sometimes fewer and short; achenes glabrous; pappus white.
In moist soil on banks and in woods, Maine and Vermont to Florida, Ohio, Michigan, Alabama and Texas. Races differ in size, leaf-form, number and size or rays. Apparently erroneously recorded from Nova Scotia and Ontario. April-June.
Senecio Crawfordii Britton, Torreya 1: 21. 1901. S. Balsamitae var. Crawfordi Greenman, Rhodora 10: 69. 1908.
Perennial, glabrous, or with sparse woolly pubescence below; stem slender, about 16' high. Leaves thick, firm, the basal ones erect, the larger 8'-10' long, the blades oval, oblong, or some of them narrowly obovate, mostly not more than one-half as long as the slender petioles, sharply and nearly equally serrate from the apex to the entire cuneate base; stem leaves lanceolate or narrower, mostly acuminate, incised-serrate, clasping, the upper sessile, the lower petioled, the uppermost very small; heads 3-7; peduncles slender, bracted, rarely forked; involucre 4" high, its bracts linear-lanceolate, acuminate, shorter than the white barbellate pappus; rays 4"-5" long; achenes linear, striate.
Wet meadows, southeastern Pennsylvania. May-June.