Rydberg : Rocky Mountain flora 055 



has very narrow, linear outer bracts and usually purplish or bluish 

 rays. A. Ostcrhoiitii grows along ditches at an altitude of about 

 1500 m. 



Colorado: New Windsor, 1899, OstcrJiout 2^06 (\.yi^€)\ also 

 1898, p, and 1900, 2j;2S. 



Aster corymbiformis sp nov^ 



About 3 duL high ; stem strict, branched above, pubescent on 

 decurrent lines ; leaves linear, 5-8 mm. long, scabrous on the 

 margins, otherwise usually perfectly glabrous, half-clasping ; in- 

 florescence leafy, corymbiform ; heads about 8 mm. high ; bracts 

 linear-lanceolate, very acute, glabrous, rather firm, with an oblan- 

 ceolate green tip, in about 3 series of nearly equal length ; rays 

 white or purplish, about 7 mm. long and I \Vi\x\. wide. 



This is perhaps nearest related to A. paiiiciilatits, but in habit 

 reminding somewhat of A. adsccndciis. From the former it differs 

 in the strict habit, the corymbiform inflorescence and the entire 

 leaves. From A. aisccndciis it differs in the more numerous 

 heads and the bracts, the outer of which at least are oblanceolate 

 and obtuse in A. ndscciidcns. 



Colorado: West Clift', 1896, Slicar J460 (type); also j8ij 

 and ^Sig; Parlin, Gunnison Co., 1901, />'. H. Smith 11^ and 

 ij6 (?). 



Aster Tweedyi sp. nov. 



Perennial with a horizontal rootstock ; stem simple, usually 

 purplish, pubescent only on decurrent lines, about 4 dm. high ; 

 leaves oblanceolate, acute, glabrous except the ciliate margin, 

 rather firm, often i dm. long ; the lower with a winged petiole ; 

 the upper sessile and half clasping ; inflorescence paniculate, leafy ; 

 heads about i cm. high ; bracts in about 3 series, linear or ob- 

 lanceolate, not very unequal in length, the outer mostly green and 

 obtuse, the inner with green tips and midrib, whitish on the sides 

 below ; rays rose or purple, 8—10 mm. long and 1.5 mm. wide . 



This species is related to A. adsccndcns but differs in the stouter 

 habit, broader and firmer leaves and larger heads. It grows in 

 valleys at an altitude of 1500—2600 m. 



Wyoming: Copperton, 1901, Tivccdy ^ogd {Xy^^it); Big Horn 

 Mountains, 1899, Tweedy 2^2 j ; Laramie, i?,g'/, Elias Nelson ij2. 



Colorado: Laramie River, Larimer County, 1897, OsterJujii 

 2518. 



