136 Rydberg : Rocky Mountain flora 



plant. The writer made such a ruling in 1901, when he raised 

 A. Ricliardsonii, var. gigantea to specific rank. But it is evident 

 from Richardson's description that his A. montamis characterized 

 rather the more villous-tomentose plant. Not only was Sprengel's 

 A. Ricliardsonii based upon A. montamis Richardson, but his 

 description also characterizes Hooker's var. gigantea. 



The synonymy of the more southern plant is as follows : 



Aster meritus A. Nelson, Bot. Gaz. 37 : 269. 1904 



Aster montamis Richardson, App. Frankl. Journ. 32, in part (?). 



1823. 

 Aster Ricliardsonii Hook. Fl. Bor.-Am. 2: 7. 1834. Not A. 



Ricliardsonii Spreng. 1826. 

 Aster sibiricus A. Gray, Syn. Fl. I 2 : 176. 1884. Not A. sibiricns 



L. 1753- 



Aster Williamsii sp. nov. 



Perennial, with cespitose rootstock ; stems erect, about 3 dm. 

 high, more or less villous ; leaves oblanceolate, 3-10 cm. long, 

 the lower petioled, the upper sessile, finely villous on both sides ; 

 heads few in a corymbiform inflorescence; involucres 8 mm. high, 

 1 cm. broad ; bracts linear or lance-linear, acute, sparingly and 

 finely villous on the back, slightly scarious-margiried below, im- 

 bricate in 3 series ; rays lilac, about 1 cm. long ; achenes spar- 

 ingly and finely pilose ; pappus tawny. 



This species is somewhat intermediate between Aster andinus 

 and A. meritus. From the former it differs in the taller and more 

 slender, erect stem, the finely villous leaves, the shorter, more 

 numerous and more pubescent involucral bracts ; and from the 

 latter in the narrower leaves, which are always entire, in the com- 

 paratively higher involucre, and the narrower bracts. 



Wyoming : Dry hills, North Fork of Clear Creek, Big Horn 



Mountains, Aug. 12, 1898, T. A. Williams (type, in herb. N. Y. 



Bot. Gard.); eastern slope of Big Horn Mountains, headwaters 



of Clear Creek and Crazy Woman River, July 20-Aug. 15, 1900, 



Tweedy jop6A. 



Aster Macounii sp. nov. 



Perennial, with a rootstock ; stem 3-6 dm. high, sparingly 

 hispid-strigose, purple-tinged ; leaves thick, oblanceolate or lance- 

 olate, 2-8 cm. long, hispidulous-ciliate, otherwise glabrous; in- 



