55 2 



i i i.MI'OSITAK. 



Vol.. III. 



10. Cirsium nebraskense Britton. Nebraska 

 Thistle. Fig. 4*45. 



Cardans nebraskensis Britton, in Britt. & Brown 111 Fl 

 3: 487. 1898. 



Stem densely white-woolly, apparently over i high. 

 Leaves linear-oblong to lanceolate, white-woolly be- 

 neath, green and sparingly loosely woolly above, ir- 

 regularly slightly toothed or entire, the upper 3-6' 

 long, l'-i' wide, the margins prickly; heads solitary, 

 or few, short-peduncled, about lV high; outer bracts 

 of the involucre lanceolate, prickle-tipped, the inner 

 narrower with a reflexed acute scarious appendage; 

 pappus bristles of inner flowers plumose, of the outer 

 barbellate. 



\\ 1 stern Nebraska and Wyoming. Summer. 



11. Cirsium odoratum (Muhl.) Iiritton. 



Pasture Thistle. Fragrant Thistle. 



Fig. 4646. 



Cnicus odoratus Muhl. Cat. 70. 1813. 

 Carduus pumilus Nutt. Gen. 2: 130. 1818. 

 Cnicus pumilus Torr. Compend. 2H2. 1826. 

 Carduus odoratus Porter, Mem. Torr. Club 5 : 345. 

 1894. 



Biennial, more or less villous-pubescent ; stem 

 stout, simple or branched, leafy, i-3 high; roots 

 thick, branched, solid ; stem leaves green both sides, 

 sessile and clasping, oblong or oblong-lanceolate in 

 outline, acute, 3-7' long, 1-2' wide, pinnatifid into 

 triangular, acute, dentate, prickly lobes. Basal 

 leaves petioled; heads solitary, terminal, 2-3' 

 broad, about 2 high, often involucrate by the 

 upper leaves; outer bracts lanceolate or ovate- 

 lanceolate, with a slight glutinous strip on the 

 back, glabrous or sparingly tomentose. tipped with 

 slender prickles, the inner narrow, long-acuminate ; 

 flowers purple, rarely white, fragrant; tips of the 

 pappus bristles usually spatulate. 



In fields, Maine to Pennsylvania. Delaware and 

 West Virginia. July-Sept. 



" i.wki/ 



12. Cirsium Hillii (Canby) Fernald. 

 Hill's Thistle. Fig. 4647. 



Cnicus Hillii Canby, Gard. & For. 4: 101. 1891. 

 Carduus Hillii Porter, Mem. Torr. Club 5 : 344. 1894. 

 Cirsium Hillii Fernald. Rhodora 10: 95. 1908. 



Perennial, low, villous-pubescent or somewhat 

 woolly; stem leafy, simple or branched. l-2 

 high; root perpendicular, fusiform, slender and 

 hollow above, enlarged below, 8-12' long ; leaves 

 green both sides, mostly obtuse, lobed or pin- 

 natifid, the lobes mostly broad and rounded, den- 

 tate, spinulose or with some rather stout prickles, 

 the upper oblong, sessile and clasping, the lower 

 spatulate-oblong, narrowed at the base or the 

 lowest ones petioled and 6'-8' long; heads 2-3' 

 broad, about 2' high ; outer bracts of the invo- 

 lucre ovate-lanceolate, tipped with short bristles, 

 conspicuously glutinous on the back, the inner 

 narrowly lanceolate, long-acuminate ; flowers pur- 

 ple ; pappus bristles slender-pointed or some of 

 them slightly spatulate. 



Tn fields, western Ontario to Minnesota, south to 

 Pennsylvania, Illinois and Iowa. June-July. 



