488 



COMPOSITAE. 



[Vol. III. 





'>3 



10. Carduus odoratus (Muhl.) Porter. Pasture Thistle. Fragrant Thistle. 



(Fig. 4C67.) 



Cnicus odora/iis Muhl. Cat. 70. 1813. 

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

 Cnicus pumilus Torr. Compend. 282. 1826. 

 Carduus odoratus Porter, Mem. Torr. Club, S: 345- 



1S94. 



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-lan- 

 ceolate in outline, acute, 3'-/' long, i'-2' wide, 

 pinnatifid into triangular acute dentate prickly 

 lobes; basal leaves petioled; heads solitarj', termi- 

 nal, 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-acum- 

 inate; flowers purple, rarely white, fragrant; tips 

 of the pappus-bristles usually spatulate. 



In fields, Maine to Pennsylvania and Delaware. 

 ]uly-Sept. 



II. Carduus Hillii (Cauby) Porter. 

 Hill's Thistle. (Fig. 4068.) 



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

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



1894. 



Biennial ? low, villous-pubescent or somewhat 

 woolly; stem leafy, simple or branched, i°-2° 

 high. Root perpendicular, fusiform, slender 

 and hollow above, enlarged below, S'-I2' long; 

 leaves green both sides, mostly obtuse, lobed or 

 pinnatifid, the lobes mostly broad and rounded, 

 dentate, 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'-S' long; 

 heads 2'-3' broad, about 1' high; outer bracts 

 of the involucre ovate-lanceolate, tipped with 

 short bristles, conspicuously glutinous on the 

 back, the inner narrowly lanceolate, long-acu- 

 minate; flowers purple; pappus-bristles slender- 

 pointed or some of them slightly spatulate. 



In fields, western Ontario to Minnesota, south to Pennsylvania, Illinois and Iowa. June-July. 



12. Carduus spinosissimus Walt. 

 Yellow Thistle. (Fig. 4069.) 



Carduus spinosissimus'^a\\.. FI. Car. 194. 17S8. 

 Cirsium horridulum Michx. Fl. Bor. Am. 2; 90. 1803. 

 Cnicus horridulus Pursh, Fl. Am. Sept. 507. 1814. 



Biennial or perennial, somewhat woolly w-hen young, 

 but becoming glabrate; stem branched, leafy, 2°-5° 

 high. Leaves green both sides, lanceolate or oblong 

 in outline, sessile and clasping or the basal ones short- 

 petioled and somewhat spatulate, pinnatifid into tri- 

 angular or broader, spinulose-margined and prickle-tip- 

 ped, entire or dentate lobes; heads involucrate by the 

 upper leaves, 2'-4' broad, i^z'-^'i' high; bracts of the 

 involucre narrowly lanceolate, roughish and ciliate, 

 long-acuminate, unarmed; flowers pale yellow, yel- 

 lowish, or occasionally purple. 



In moist or dry sandy soil, Maine to Pennsylvania, 

 Florida and Texas. Abundant along the edges of salt- 

 meadows in New York and New Jersey. May-Aug., or 

 earlier in the South. 



