84 KEY TO THE SPECIES 



8. Balsamorrhiza. Disk flat, yellow ; pappus none ; outer bracts of the 

 broad involucre toliaceous. ' 



+- -I- Eeceptacle naked or fimbrillate ; pappus of 5-12 hyaline scales ; aohenes 

 turbinate or ob-pyramidal. 



9. Tetraneuris. Bracts of involucre similar ; receptacle naked : mostly 

 ceespitose plants with scapose stems, and yellow flowers. 



10. GalUardia. Bracts of involucre dissimilar : receptacle with slender 

 fringed bracts ; leafy stemmed plants with large yellow rays and disk-flowers 

 becoming brownish. 



•1- -I- -I- Receptacle naked ; pappus of numerous capillary bristles ; achenes 

 slender ; disk yellow. 



11. Stenotus. Low ceespitose, with woody base, narrow alternate leaves, 

 and scapose stems. 



12. Arnica. Herbs ; leaves few, opposite ; heads solitary or few, rather 

 large, conspicuously radiate. 



13. Senecio. Herbs ; leaves alternate ; heads few to many in a cymose- 

 corymb or panicle ; rays few. 



1. TOWNSENDIA 



Depressed, tufted, or spreading from the branched base, with narrow entire 

 leaves, large heads with numerous rays ; the bracts of the involucre imbricated in 

 several series (the outer shorter), the achenes compressed and pubescent with 

 hairs forked at the tip. 



* Stemless, depressed, heads medium-sized (lB-80 mm. broad). 



1. Townsendia exscapa (Rich.) Porter. (Eaklt Tow.nsendia). Sericeous 

 pubescent, closely appressed to the ground ; heads solitary or several (when 

 several crowded), more or less exceeded by the numerous spatulate-linear leaves 

 which form a rosulate cluster about the heads ; involucral bracts nearly linear, 

 acute : rays generally white. Exceedingly abundant ; plains and foothills ; the 

 earliest of the flowers. 



* Stems branched from the base ; heads large, 3 cm. or more broad. 



2. Townsendia grandiflora Nutt. (Large-flowebed Townsendia). Canes- 

 cently pubescent, becoming glabrate ; the stems ascending, often branching ; 

 leaves from spatulate to linear, the uppermost subtending the head ; involucral 

 bracts lanceolate, scarious margined ; rays violet-purple to white ; pappus of disk 

 flowers longer than the achene. 



3. ERIGERON (Erigeron. Fleabane) 



Herbs with entire or toothed alternate leaves, solitary or clustered heads on 

 naked peduncles, narrow and nearly equal involucral scales, variously colored 

 rays, yellow disk, flattened 2-nerved achenes, and pappus of capillary bristles. 



* Leaves pedately trifld. 



1. Erigeron trifidus Hook. (Birdfoot Erigeron). Dwarf and tufted, with 

 short hirsute pubescence ; leaves crowded on the numerous crowns or short .stems 

 of the depressed caudex, the short blade 3-5-parted into linear oblong divisions 

 which are sometimes again cleft or lobed, on slender hirsute petioles 2-6 times as 

 long as the blade ; peduncles slender, usually much surpassing the leaves, mono- 



