GENUS 31. 



THISTLE FAMILY. 



427 



55. Aster vimineus Lam. Small White Aster. Fig. 4336. 



Aster vimineus Lam. Encycl. i : 306. 1783. 



Aster foliolosus Ait. Hort. Kew. 3: 203. 1789. 



Aster Tradescanti T. & G. Fl. N. A. 2 : 129. 1841. Not 



L. 1753- 

 Aster vimineus foliolosus A. .Gray, Syn. Fl. i : Part 2, 



1 86. 1884. 



Glabrous or nearly so throughout ; stem slender, 

 divergently branched, 2-5 high. Stem leaves linear- 

 lanceolate, entire, or with a few low teeth, 3'-$' 

 long, 2"~4" wide, acuminate at the apex, narrowed 

 to a sessile base, those of the branches much smaller ; 

 heads very numerous, small, -3"-5" broad, 2"-3" 

 high, generally densely racemose-secund, sometimes 

 subpaniculate, short-peduncled ; involucre broadly 

 turbinate, its bracts linear, acute or acutish, imbri- 

 cated in about 3 series, green-tipped, appressed ; 

 rays numerous, about 2" long, white to purplish ; 

 pappus white; achenes minutely pubescent. 



In moist soil, Ontario to Florida, west to Minnesota 

 and Arkansas. Aug.-Sept. 



Aster racemosus Ell., with smaller heads, the leaves 

 all very small, of the Southeastern States, apparently 

 occurs in extreme southern Illinois. 



56. Aster multiflorus Ait. Dense-flowered 

 Aster. White Wreath Aster. Fig. 4337. 



Aster multiflorus Ait. Hort. Kew. 3: 203. 1789. 



A. multiflorus stricticaulis T. & G. Fl. N. A. 2 : 125. 1841. 



A. multiflorus exiguus Fernald, Rhodora i : 187. 1899. 



A. exiguus Rydb. Bull. Torr. Club 28: 505. 1901. 



A. polycephalus Rydb. Bull. Torr. Club 33: 153. 1906. 



Stem strict, much branched and bushy, rough- 

 pubescent or scabrous, i-7 high, the branches as- 

 cending or spreading. Leaves rigid, linear or linear- 

 oblong, entire, mostly obtuse, sessile or slightly 

 clasping at the base, rough and ciliate, those of the 

 stem i-ii' long, those of the branches very small 

 and crowded ; heads 3" -4" broad, densely crowded, 

 nearly sessile, sometimes slightly secund on the 

 branches; involucre 2" -3" high, its bracts coriaceous, 

 mostly ciliate or pubescent, in 3 or 4 series, their 

 short green tips obtuse or mucronate, spreading ; 

 rays 10-20, white, i$"-2" long; pappus brownish 

 white; achenes puberulent. 



In dry open places, Maine and Ontario to Alberta, 

 Georgia, Texas and Arizona. Consists of many slightly 

 differing races. Fall-flower. Aug.-Nov. 



57. Aster commutatus (T. & G.) A. Gray. 

 White Prairie Aster. Fig. 4338. 



Aster ramulosus var. incanopilosus Lindl. in DC. Prodr. 5 : 



243. 1836. 

 Aster multiflorus var. commutatus T. & G. Fl. N. A. 2 : 125. 



1841. 



Aster commutatus A. Gray, Syn. Fl. i : Part 2, 185. 1884. 

 A. incanopilosus Sheldon, Bull. Torr. Club 20: 286. 1893. 



Similar to the preceding species, except in the inflores- 

 cence, the stem rough-pubescent, or sometimes nearly 

 glabrous, ii-2-l high, with ascending or divergent 

 branches. Leaves linear or linear-oblong, obtuse, entire, 

 sessile or slightly clasping at the base, those of the stem 

 i' 3" long; heads larger than those of A. multiflorus, 

 6"-8" broad ; involucre 3 "-4" high, its ciliate bracts 

 squarrose-tipped and sometimes foliaceous; rays 20-30, 

 about 3" long. 



On prairies and along rivers, Minnesota to Saskatchewan, 

 Nebraska, Texas and New Mexico. Aug.-Oct. 



