i i IMPOSITAE. 



Vol. 111. 



15. Senecio Robbinsii Oakes. Robbins' 

 Squaw-weed. Fig. 4624. 



Senecio Robbinsii Oakes; Rusby, Bull. Torr. Club 20: 

 19. 1893. 



Perennial, glabrous or very nearly so through- 

 out ; stems slender, l-2i high. Basal leaves 

 long-petioled, lanceolate, obtuse or acute at the 

 apex, cordate, subcordate or truncate at the base, 

 usually thin, 2-4' long, V-iY wide, sharply den- 

 tate ; stem leaves mostly pinnatifid or lobed, at 

 least below the middle; heads several or numer- 

 ous, slender-peduncled in an open corymb, 8"-io" 

 broad; rays 6-12; achenes glabrous or pubescent; 

 pappus white. 



In swamps and mountain meadows, Nova Scotia to 

 New Hampshire, Vermont and New York. June- 

 Sept. 



16. Senecio aureus L. Golden Ragwort. 



Life-root. Swamp Squaw-weed. 



Fig. 4625. 



Senecio aureus L. Sp. PI. 870. 1753. 



Senecio pauciflorus Pursh, Fl. Am. Sept. 529. 1814. 



Senecio gracilis Pursh, Fl. Am. Sept. 529. 1814. 



Perennial, glabrous or very nearly so through- 

 out ; stems rather slender, solitary or tufted, 

 6'-2j high. Basal leaves cordate-ovate or 

 cordate-orbicular or reniform, crenate-dentate, 

 very obtuse and rounded, often purplish, i'-6' 

 long, with long slender petioles ; lower stem 

 leaves lanceolate or oblong, usually laciniate. 

 pinnatifid or lyrate, the uppermost small, ses- 

 sile, somewhat auriculate and clasping; heads 

 usually several, 8"-io" broad, 4"-$" high, slen- 

 der-peduncled in an open corymb; rays 8-12, 

 golden-yellow; achenes glabrous; pappus white. 



In swamps and wet meadows, Newfoundland to 

 Florida, Ontario, Michigan, Missouri and Texas. 

 Grandy-swallow. False-valerian. Root strong- 

 scented. Races differ in size of plant, size of 

 leaves and number of heads. May-July. 



Senecio pseudaiireus Rydb. (S. semi-cordatus Mac- 

 kenzie & Bush), of the Rocky Mountain region, differing 

 by elliptic or broadly oblong basal leaves, ranges east- 

 ward into North Dakota and Missouri. 



17. Senecio discoideus (Hook) Britton. 

 Northern Squaw-weed. Fig. 4626. 



Senecio aureus var. discoideus Hook. Fl. Bor. Am. 1 : 



333- iS33- 

 Senecio discoideus Britton, in Britt. & Brown, 111. Fl. 



3: 479. 1898. 



Perennial, glabrous except for small tufts of wool 

 in the axils of the lower leaves; stem rather stout, 

 i-2i 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 invo- 

 lucre narrowly linear, 3"-S" long, the short outer 

 ones few or none; rays none; achenes glabrous. 



In moist places. Labrador to Yukon, Quebec, Michi- 

 gan, Wyoming and British Columbia. June-Aug. 



