206 COMPOSITAE 



40. TANACBTUM L. 



Perennials with alternate pinnatifid leaves and corymbose heads. In- 

 volucre imbricated. Marginal flowers fertile. Pappus a short crown. 



1. T. vulgare L. TANSY. Smoothish, l-4 high : heads about 4" 

 broad : marginal flowers with short 3-toothed limbs. Occasionally escap- 

 ing from gardens to roadsides. August-September. 



41. ARTEMISIA L. WORMWOOD. 



Alternate-leaved herbs with small paniculate heads of flowers. Invo- 

 lucre imbricated. Pappus none. 



Leaves glabrous or nearly so on both sides. 



Upper leaves linear, entire. 1. A. dracunculoides. 



Upper- leaves pinnately parted. 



Plant strongly sweet scented. 2. A. annua. 



Plant not sweet-scented. 3. A. liennis. 



Leaves strongly tomentose on both sides. 



Leaves pinnatifid. 4. A. Carruthii. 



Leaves entire. 5. A. gnaphalodes. 



Leaves glabrate above ; tomentose beneath. 



Stem strongly tomentose. 6. A. Ludoviciana. 



Stem glabrate. 7. A. Mexicana. 



1. A. dracunculoides Pursh. Perennial, l-4 high, glabrous : 

 lower leaves somewhat pinnatifid : disk flowers sterile. Occurs locally 

 in barrens east of Dodson and west and north of Lee's Summit. August- 

 October. 



2. A. annua L. Annual, l-5 high, glabrous: leaves 2-pinnatifid : 

 heads paniculate : flowers all fertile. Sparingly adventized at Kansas 

 City and Independence. August-November. 



3. A. biennis Willd. Annual or biennial, l-3 high, glabrous : 

 leaves once pinnatifid, the divisions serrate : heads almost spicate : flow- 

 ers all fertile. Shore of the Missouri River ; rather infrequent. August- 

 November. 



4. A. Carruthii Wood. IZ'-W high, much branched, short white- 

 canescent : lower leaves pinnatifid into 5-7 narrowly linear segments : 

 upper leaves linear, entire : flowers all fertile. Occurs rarely as a waif 

 at Sheffield. September-October. (A. Kansana Britton.) 



5. A. gnaphalodes Nutt. Perennial, l-3 high : stems tomentose : 

 upper leaves lanceolate or linear-lanceolate, entire : lower leaves more or 

 less incised but not pinnatifid : flowers all fertile : involucre hardly 

 tomentose-canescent : heads usually not nodding, \\" long. Sandy bot- 

 toms along the Missouri River near Courtney and Sibley. Not common. 

 July-October. 



6. A. Ludoviciana Nutt. Stems 15 / -30 / high, stout, densely white- 

 tomentose : leaves as in A. Mexicana Willd.: heads often nodding, 2 X/ 

 long : involucre densely white tomentose-canescent. Dry barrens and 

 prairies throughout the southern part. September-October. 



