504 Rydberg : Studies on the Rocky Mountain Flora 



filiform, 1-2 cm. long, less than i mm. wide, dark green and 

 glabrous except the minutely scabrous-ciliolate margins : cyme 

 large, flat-topped : heads very numerous, 5-6 mm. high, 2 mm. 

 in diameter, turbinate ; bracts in 5 vertical rows with usually 3 in 

 each row, lanceolate-acuminate, the outer with green tips, the 

 inner wholly chartaceous. 



In habit and leaves, this species resembles C. stciiophylhis, but 

 the leaves are still narrower and in that species the bracts are 

 obtuse or merely acute. 



Colorado: Granite, i2>g6, Fred. C/cmcuts, jgo. 



Chrysothamnus scoparius sp. nov. 



Perennial with a woody caudex and deep tap-root. Stems 1-2 

 dm. high, glabrous and shining, with a white bark : leaves nar- 

 rowly linear, light bluish-green, glabrous, 2-3 cm. long, a little 

 over I mm. wide, more or less twisted : cyme flat-topped : heads 

 numerous, 6-8 mm. high, 2-3 mm. wide ; bracts chartaceous, 

 lanceolate, acuminate. 



This .species is still more like C. stciiopJiyllus in habit, but the 

 bracts are different, being acuminate instead of obtuse or acute 

 and more keeled. The perennial portion is also much shorter and 

 the general color of the plant is much lighter. 



Colorado : Mesas, La Veta, 1900, F. K. Vrccland, 6gS. 



Aster crassulus sp. nov. 



Aster miiltifloriis A. Gray, PI. Wr. 2 : 75. In part. 1853. 



Aster incano-pilosns Rydb. Mem. N. Y. Bot. Gard. I : 393. 

 In part. 1900. 



Perennial with a horizontal, stoloniferous rootstock. Stems 

 erect or ascending or rarely decumbent, usually simple below, 

 branched above, 4-7 dm. high, terete, brownish, densely hirsute 

 with short divaricate hairs : stem-leaves linear, or oblong-linear, 3- 

 6 cm. long, 2-t^ mm. wide, rather firm, hirsute with short spreading 

 hairs, sessile and slightly clasping, in age usually reflexed, acute 

 with a short spinulose tip; those of the branches smaller; those 

 of the branchlets only 3-5 mm. long and merging into the bracts 

 of the involucres : heads numerous, borne at the end of leafy 

 branchlets which are 1-2 cm. long ; involucre turbinate, 5-8 mm. 

 high, 8-10 mm. broad ; bracts in 3-4 series, the outer successively 

 shorter, broadly spatulate, minutely spinulose-mucronate, very 

 thick, hirsute especially on the margin, chartaceous at the base 

 with a broadly oval herbaceous tip : rays numerous, white, 5-7 

 mm. long and fullv i mm. wide : achenes strigose. 



