Genus 8S.] 



THISTLE FAMILY 



i6. Artemisia serrata Niitt. 

 Saw-leaf Mugwort. (Fig. 4013.) 



Arlemisia serrata Xutt. Gen. 2: 142. 181S. 



Perennial; stem stout, tomentose or be- 

 coming glabrous, much branched, 5°-io° 

 high. Leaves lanceolate, 2'-6' long, 3"- 

 12" wide, densely while-tomentose beneath, 

 dark green and glabrous above, acuminate 

 at the apex, narrowed to a sessile base, or 

 the lowest petiolcd, sharply serrate or in- 

 cised, or the upper entire; heads very nu- 

 merous, greenish, erect, about iK" broad, 

 sessile or shortpeduncled in panicled spikes 

 or racemes; involucre canescent, its bracts 

 oblong, obtuse, or the outer ones lanceolate; 

 receptacle naked; central flowers fertile. 



Prairies, Illinois to Minnesota and Dakota. 

 Introdnced on the Mohawk River, near Sche- 

 nectady, N. V. .-iug.-Oct. 



17. Artemisia longifolia Nutt. 

 Long-leaved Mugwort. (Fig. 4014.) 



Arlemisia longifolia Nutt. Gen. 2: 142. 181S. 

 Perennial; stem densely white-tomentose, 

 branched, 2°-5° high. Leaves linear or lin- 

 ear-lanceolate, elongated, entire, 2'-$' long, 

 i"-5" wide, acuminate, tapering to a sessile 

 base, or the lower petiolcd, densely white- 

 tomentose on both sides, or becoming green 

 and glabrate above; heads numerous, erect, 

 spicate-paniculate, about 2" broad; involucre 

 tomentose, its bracts oblong, obtuse; recep- 

 tacle naked; central flowers fertile. 



In dry rocky soil, western Nebraska to Min- 

 nesota, Montana and the Northwest Territory. 

 Aug.-Sept. 



18. Artemisia gnaphalodes Xtitt. 



Prairie, Western or Cud-weed 



Mugwort. (Fig. 4015.) 



Arlemisia gnaphalodes Nutt. Gen. 2: 143. 1818. 

 Artemisia Ludoviciana var. gnaphalodes T. & 

 G. Fl. N. A. 2: 420. 1843. 



Perennial, similar to the preceding spe- 

 cies; stem white-tomentose, usually much 

 branched, i°-4° high. Leaves lanceolate or 

 oblong, I '-3' long, 2"-6" wide, entire, or 

 the lower somewhat toothed, lobed or in- 

 cised, white tomentose on both sides, acute 

 or acuminate, sessile or the lower narrowed 

 into short petioles; heads numerous, erect, 

 spicate-paniculate, above i%" broad; invo- 

 lucre oblong, tomentose; receptacle naked; 

 central flowers fertile. 



On prairies and dry banks, western Ontario 

 and Illinois to British Columbia, south to Mis- 

 souri, Texas. Arizona, Blexico and California. Aug.-Oct 



