ARTEMISIA 255 



1. Basal leaves, and often some stem leaves, deeply 



heart-shaped, densely hairy to smooth or near- 

 ly so A. cor di folia 



2. Leaves not cordate 



a. Stem leaves usually 4-8 pairs 



(1) Leaves lance-ovate to lanceolate or ob- 



long, acute or blunt at tip, 2-3 in. long A. Chamissonis 



(2) Leaves long lanceolate, 3-6 in. long, taper- 



ing into a point 1-2 in. long A. longi folia 



b. Stem leaves 1-3 pairs, upper pair usually bract- 



like 



(1) Heads without rays, usually 3-13; leaves 



lance-ovate to lanceolate A . Pdrryi 



(2) Heads with rays, single or 2-3; leaves 



ovate to lanceolate A.alpina 



ARTEMISIA Linne 1753 WORMWOOD, SAGEBRUSH 



(Named for Artemisia, wife of Mausolus) 



Heads without ray-flowers, the disk-flowers all perfect and fertile, or 

 the central ones sometimes sterile, the marginal ones pistillate and fertile, 

 achenes obovate to oblong, pappus none ; receptacle flat to hemispheric, 

 without chaff, involucre oblong to hemispheric, the bracts imbricated in a 

 few rows ; heads variously clustered, the flowers greenish or yellow ; leaves 

 alternate, entire to divided, often woolly; herbs or shrubs. 



1. Stems spiny; achenes cobwebby with long hairs; 



leaves digitately 3-5-parted A. spinescens 



2. Stems not spiny; achenes not cobwebby 

 a. Stems shrubby, 5 in. to 10 ft. high 



(1) Leaves entire, linear to lance-linear, dense- 



ly white-hairy; stems 1-2.5 ft. high A.cdna 



(2) Leaves 3-toothed or 3-cleft 



(a) Leaves wedge-shaped, 3-toothed or 3- 



lobed at the tip, uppermost entire 



x. Stems usually 1-10 ft. high; flower 

 cluster much branched ; heads 2 mm. 

 wide A. tridentdta 



y. Stems 4-10 in. high ; flower cluster nar- 

 row, spike-like ; heads 3 mm. wide A. arbuscula 



(b) Leaves 3-cleft into thread-like lobes, the 



upper entire and thread-like 

 x. Leaves 1-2 cm. long, lobes 3-10 mm. 



long ; heads oblong, 2 mm. wide A. trifida 



