COMPOSITAE. 



[Vol. III. 



55. Aster acuminatus Michx. 

 Whorled or Mountain Aster. (Fig. 3789. ) 



Aster divaricaltis Lam. Encycl. i: 305. 17S3. 



Not L. 1753- 

 Asler acuminaliis Michx. Fl. Bor. .^111.2:109. 1803. 



Stem pubcsccut or puberulent, zigzag, cor- 

 ynibosely branched, often leafless below, i°- 

 3° high. Leaves thin, broadlj' oblong, acumi- 

 nate at the apex, narrowed to a somewhat 

 cuneate sessile base, sharply and coarsely den- 

 tate, piunateh' veined, glabrous or pubescent 

 above, pubescent at least on the veins beneath, 

 3'-6' long, Yi'-iyi' wide, often approximate 

 above, and appearing whorled; heads several 

 or numerous, I'-l/z' broad; involucre nearly 

 hemispheric, its bracts subulate-linear, acumi- 

 nate, the outer much shorter; rays 12-1S, nar- 

 row, 6"-S" long, white or purplish; pappus 

 soft, fine, nearly white; achenes pubescent. 



Moist woods, I.abrador to Ontario, western New 

 York, and in the mountains to Georgia. July-Oct. 



56. Aster ptarmicoides (Nees) T. & G. Upland White Aster. (Fig. 3790.) 



Chiysopsis alba Nutt. Gen. 2: 152. 181S. Not 



A. albiisWxWA. 

 Doellingeria ptarmicoides Nees, Gen. & Sp. 



Ast. 183. 1832. 

 A. ptarmicoides T. & G. Fl. N. .\. 2: 160. 1841. 



Stems tufted, slender, rigid, usually rough 

 above, corymbosely branched near the sum- 

 mit, i°-2° high. Leaves linear-lanceolate, 

 3-ribbed, entire, or with a few distant teeth, 

 firm, shining, rough-margiucd or ciliate, 

 sometimes scabrous, acute, narrowed to a 

 sessile base, or the lower petioled, the low- 

 est and basal ones 3'-6' long, 7."-\" wide, 

 the upper smaller, those of the branches 

 linear-subulate; heads not numerous, S"- 

 12" broad, terminating the branches of the 

 corymb; involucre nearly hemispheric, 1"- 

 3" high, its bracts linear-oblong, obtuse, ap- 

 pressed, nearly glabrous.green, imbricated in 

 abovit 4 series; rays 10-20, snow white, 3"- 

 4" long; pappus white; achenes glabrous. 



In dry or rocky soil, Massachusetts, Vermont 

 and Ontario, to the Northwest Territory, Illi- 

 nois, Missouri and Colorado. July-Sept. 



Aster ptarmicoides lutescens (Hook.) .A. Gray, Syn. Fl. i: Part 2, 199. 1SS4. 

 Diplopappus albiis var. lutescens Hook. Fl. Bor. Am. 2: 21. 1834. 



Rays pale yellow, short: involucre narrower. 

 Northern Illinois to the Northwest Territory. 



57. Aster dumosus L. Bushy Aster. 

 Rice-button Aster. (Fig. 3791.) 



Aster du7nosus h. Sp. PI. S73. 1753- 



Glabrous or very nearly so throughout, paui- 

 culately much branched, i°-3° high. Leaves 

 firm, those of the stem linear or linear-lanceo- 

 late, entire, acute, orobtusish, i'-3' long, i>^"-j''' 

 wide, roughishmargined, often reflexed, those 

 of the branches very numerous, small and bract- 

 like, the basal ones spatulate, dentate; heads 

 4"-7" broad, terminating the usually divergent 

 slender branches and branchlets, usually numer- 

 ous; involucre broadly camjianulate, its bracts 

 linear-subulate, obtuse or aculish, appressed, im- 

 bricated in about 4 series, green-tipped; rays 15- 

 30, white to pale violet, 2" long, pappus white; 

 achenes minutely pubescent. 



Sandy soil, Massachusetts to western New York, 

 Ontario, Florida, Louisianaand Missouri. Aug.-OcL 



