KEY. 279 



row, bristly-toothed segments. Heads terminating the 

 branches ; rays few, yellow. 



Dysodia chrysauthemoides, Lag. 



948. Rays sterile, wedge-form, yellow. Agreeing in all 

 other respects with Helenium. 



Leptopoda brachypoda, Torr. & Gr. 



Rays fertile, wedge-form, 3- to 5-cleft. Recepta- 

 cle spherical ; involucral scales linear, reflexed. Achenia 

 top-shaped, ribbed. Pappus of 5-8, chaffy, 1 -nerved, bristle- 

 pointed scales. Leaves lanceolate, toothed, decurrent on the 

 angled stem and branches. Heads yellow, at the end of the 

 branches, or corymbed. Helenium autumnale, L. 



949. Leaves alternate 952 



Leaves opposite or radical 950 



950. Leaves radical 951 



Leaves opposite. Scales of the involucre in 2 rows. 

 Pappus of rough, denticulate bristles. Heads large, solitary, 

 or corymbed ; flowers yellow. Stem simple. Arnica. 



951. Heads purplish ; flowers fragrant. Herb somewhat 

 dioecious. Leaves roundish, or kidney-shaped, deeply 5- to 

 V-lobed, the lobes toothed and cut, white- woolly beneath, 

 very large. Scape with sheathing scaly bracts. Corymb. 



Nardosmia palmata, Hook. 

 [Siceet Coltsfoot.) 



Heads yellow, solitary, with fertile flowers in tlie 

 ray and sterile ones in the disk. Scape simple, with purple 

 scales, appenring with its flower before the leaves. Leaves 

 heart-shaped, angular, toothed, woolly beneath, long-petioletl. 



Tussilago farfara, L. 



9od. Rays whitish or purple 953 



Rays yellow, in about one row (very rarely cream- 

 color) , 957 



953. Rays in a single row, pistillate and fertile 954 



Rays in several rows. Erigeron (950) 



954. Pappus simple 955 



Pappus double. Rays 8-12. Heads corymbose or 



solitary. Diplopappus, Cass. 



