Genus 95.] 



THISTLE FAMILY. 



479 



Senecio obovatus rotiindus Britton. 

 Basal leaves orbicular, broadly oval, or ovate-orbieular, rather abruptly narrowed into the peti- 

 ole, the larger 2%'-$ broad. On wet banks, or rocks, Kentucky to Missouri and the Indian Territory. 



10. Senecio discoideus (Hook) Britton. 

 Northern Squaw- weed. (Fig. 4042.) 



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

 333- l $33- 



Perennial, glabrous except for small tufts of 

 wool in the axils of the lower leaves; stem rather 

 stout, i-2 tall; basal leaves oval to ovate, obtuse, 

 thin, sharply dentate, abruptly narrowed into peti- 

 oles longer than the blade; stem-leaves few, small, 

 more or less laciniate; heads few or several, slen- 

 der-peduncled, corymbose; bracts of the involucre 

 narrowly linear, 3 // -5 // long; rays very short, or 

 none; achenes glabrous. 



In moist places, Michigan to the Northwest Territory. 

 June-Aug. 



11. Senecio Balsamitae Muhl. Bal- 

 sam Groundsel. (Fig. 4043.) 



Senecio Balsamitae Muhl.; Willd. Sp. PI. 1999. 1804. 

 Senecio aureus var. Balsamitae T. & G. Fl. N. A.> 

 2: 442. 1843. 



Perennial, often tufted, stems slender, io / -2o / 

 high, woolly at the base and in the axils of the 

 lower leaves. Basal leaves slender-petioled, 

 oblong, rarely slightly spatulate, very obtuse, 

 narrowed at the base, mostly thick, crenate, 

 often purplish, \'-2>' long, 3 // -6 // wide, their 

 petioles and sometimes their lower surfaces 

 persistently tomentose or woolly, or glabrous 

 throughout; lower stem-leaves petioled, lacini- 

 ate or pinnatifid, the upper sessile, very small; 

 heads few or several, slender-peduncled, 6 // -io // 

 broad, 3 // -4 // high; rays 8-12; achenes usually 

 hispidulous on the angles; pappus white. 



In dry or rocky soil, Nova Scotia to North Caro- 

 west to Washington, British Columbia, Texas and Nebraska. May-July. 



lina 



12. Senecio Smallii Britton. Small's 

 Squaw- weed. (Fig. 4044.) 



5". aureus VAX. a ngustifolius Britton, Mem. Torr. Club, 



2:39. 1890. Not S. august if olius Willd. 1804. 

 S. Smallii Britton, Mem. Torr. Club, 4: 132. 1893. 



Similar to the preceding species but taller, grow- 

 ing in large clumps. Stem i l / 4-2j4 high, slender, 

 densely and persistently floccose-woolly at the 

 base and in the lower axils, or finally glabrate; 

 basal leaves elongated-oblong or linear oblong, 

 obtuse or acute, long-petioled, crenate-dentate, 

 S'-V long, 3 // -9 // wide, at first tomentose, at length 

 nearly glabrous; stem-leaves several, deeply pin- 

 natifid, or the lower lyrate, the uppermost very- 

 small ; heads very numerous, 4 // ~5 // broad, about 

 2 x / 2 " high, slender-peduncled, forming large cor- 

 ymbs; rays S-10; achenes hispidulous; pappus 

 white. ' 



In meadows and thickets, mountains of Virginia 

 and North Carolina. May-June. 



