346 CARDUACEAE. 



2. Tonestus pygmaeus (T. & G.) A. Nels. {Aplopappus pygmaeus A. 

 Gray; Macroncma pygmaciim Greene) On mountains of Wyo. and Colo. — 

 Alt. 10,000-13,000 ft. — Clear Creek; Gray's Peak; Little Kate Mine, La Plata 

 Mountains ; Mt. Princeton ; Cameron Pass, Larimer Co. ; Pike's Peak ; Bald 

 Mountain; Silver Plume; Mt. Garfield; near Pagosa Peak; Beaver Creek; 

 Raton Range; Middle Park. 



19. SOLID AGO L. Golden Rod. 



Leaves glabrous or slightly pubescent along the veins and on the margins. 



Leaves not triple-veined ; branches of the inflorescence not recurved-spread- 

 ing; heads not secund. 

 Bracts of the inflorescence lanceolate or linear-lanceolate, acute or acuminate. 

 Leaves ciliate at the base. L Virgaureae. 



Leaves not ciliate at the base. IV. Gi.aberrimae. 



Bracts of the inflorescence oblong or linear-oblong, obtuse. 



Leaves, at least the basal ones, toothed ; stem-leaves few ; plants 1-4 dm. 



high. IL HuMiLES. 



Leaves all entire ; stem very leafy, 4-8 dm. high. IIL Speciosae. 



Leaves triple-veined ; heads more or less secund on recurved-spreading branches. 

 Plants slender, not very leafy, 2-4 dm. high ; stem-leaves narrowly oblan- 

 ceolate or linear. IV. Glaberrimae. 



Plant tall, leafy, 4-10 dm. high; stem-leaves lanceolate. V. Serotinae. 



Leaves densely canescent. 



Leaves lanceolate ; bracts narrowly linear-lanceolate. VI. Serotinae. 



Leaves, at least the lower ones, oblanceolate or obovate. VII. Incanae. 



I. Virgaureae. 



Plant low and slender, 1-3 dm. high ; inflorescence corymbiform ; branches with 

 a single or a few corymbose heads. 

 Heads 7-9 mm. high ; inner bracts linear-lanceolate, of about the same length 



as the flowers and pappus ; plant 2-^ dm. high. i. 5". scopulorum. 



Heads 5-7 mm. high ; bracts lanceolate ; the inner shorter than the flowers and 

 the pappus ; plant usually less than 2 dm. high. 2. 6". ciliosa. 



Plants stout. 3-4 dm. high ; inflorescence paniculate : branches racemiform : heads 

 7-9 mm. high. 

 Basal leaves broadly oblanceolate, acute ; stem pubescent. 



3. S. rubra. 



Basal leaves narrowly oblanceolate, obtuse ; stem glabrous up to the inflorescence. 



4. 5". laevicauUs. 



II. Humiles. 



Plant low, i-i.S dm. high; inflorescence with few heads, short, congested. 



5. S. decumhens. 

 Plant taller, 2-4 dm. high ; inflorescence with many heads, elongated. 



Leaves not ciliate ; bracts oblong ; inflorescence usually narrow. 



6. S. oreophila. 

 Leaves ciliate at the base ; bracts linear ; inflorescence open. 



7. 5". dilatata. 



III. Speciosae. 

 One species. 8. 5". pallida. 



IV. Glaberrimae. 



Heads less than 5 mm. high ; stem slender. 



Inflorescence decidedly viscid ; leaves indistinctly triple-veined. 



9. S. viscidula. 

 Inflorescence not viscid ; leaves distinctly triple-veined. 



