KEY TO IMPORTANT WOODY PLANTS 79 



clustered secondary leaves; branches slender, 

 wide-spreading; bark gray, shreddy; dry, open 

 sites, often with sagebrush, central and se. 

 Oreg., not reported from Wash. 

 littleleaf horsebrush (Tetradymia glabrata). 



43. Twigs and leaves permanently grayish- to 

 whitish- woolly-hairy; leaves to \)i inch long, 

 linear to reversely lance-shaped, sometimes 

 with shorter and broader leaves clustered in 

 their axils; branches nearly erect; shrubs with 

 rough, shreddy bark, not so poisonous as little- 

 leaf horsebrush; dry scablands or sagebrush 

 areas, e. Oreg., e. Wash.; type locality, along 

 the Columbia River. 



gray horsebrush {Tetradymia canescens). 

 42. Flower-head bracts more than 4, overlapping, in 

 several, often vertically ranked rows, papery, 

 leathery or leaflike, sometimes keeled; flowers 

 5-20 ' in each flower head; leaves sometimes 

 spirally twisted, 1- and/or 3- to 5-veined from 

 near base. 



rabbitbrush goldenweed (Aplopappus 



bloomeri); varieties (or subspecies) of 



Douglas rabbitbrush (Chrysothamnus 



viscidiflorus) , and of rubber rabbitbrush 



(C. nauseosus). 



44. Twigs brittle; leaves to 2K inches long, thread- 

 like to linear or reversely lance-shaped, almost 

 hairless to finely, often stiffly, short-hairy, at 

 least along margins, sometimes resinous; flower- 

 head bracts in indistinctly vertical ranks; low 

 to medium-sized shrubs, usually not more than 

 3 feet high; dry or rocky hillsides at lower 

 elevations. 



rabbitbrush goldenweed; varieties (or 

 subspecies) of Douglas rabbitbrush. 



45. Flower-head bracts leaflike or at least green- 

 tipped, with cobwebby hairs near edges and 

 stiffer, spreading hairs on margins; flower 

 heads short -stalked, bell-shaped, to % inch 

 high, often surpassed by leaves, blooming 

 May— Aug., in somewhat elongated end 

 clusters (on well-developed plants) ; ray 

 flowers 1-5, strap-shaped; disk flowers 4-12, 

 tubular; "seeds" (achenes) 5-nerved; leaves 

 1 -nerved, usually resinous, especially near 

 flower heads. 



rabbitbrush goldenweed 

 (Aplopappus bloomeri). 



45. Flower-head bracts not leaflike or green- 

 tipped as above, firm-papery, mostly blunt- 

 tipped, not keeled, usually 15; flower-head 

 cups "(involucres)" narrow, tubular-bell- 

 shaped, to % inch high; flower heads not 



471114 O-60-6 



