Gencs 31.] 



TH1STI.E FAMILY. 



371 



heads usually fewer; inflorescence racemose-corymbose. In shaded swamps, Massachusetts to 

 North Carolina. 



Aster Novi-Belgii Brittonii Burgess. 

 Leaves thick; heads short-pedunclcd, racemose-spicate toward the ends of the branches; green 

 tips of the bracts short. Massachusetts to southeastern New \ork and Virginia, near the coast. 



40. Aster longifolius Lam. Long-leaved 

 Aster. (Fig. 3774.) 



Aster longifolius Lam. Encycl. i: 306. 17S3. 



Stem glabrous, or somewhat pubescent, leafy, 

 paniculately branched, i°-3° bigh. Leaves lan- 

 ceolate to linear-lanceolate, entire or nearly so, 

 acuminate at the apex, narrowed into a sessile 

 clasping usually slightly cordate base, 3'-S' long, 

 2"-6" wide; heads rather numerous, about i' broad; 

 involucre hemispheric, 4"-5" bigh, its bracts gla- 

 brous, narrow, green, acute, imbricated in only 

 I or 2 series, nearly equal; rays numerous, about 

 4" long, violet or pale purple; pappus pale. 



In swamps and moist ground, Labrador to the North- 

 west Territory, south to northern New England, Onta- 

 rio and Montana. Summer. 



Aster longifolius villicauhs A. Gray, Svn. Fl. 1: Part 2, 

 189. 1884. 



Stem densely white-viUous; leaves narrowly linear- 

 lanceolate, the mid-rib villous beneath; heads fewer, 

 longpeduncled; rays dark violet. Northern Maine and 

 New Brunswick. 



41. Aster foliaceus Lindl. Leafy- 

 bracted Aster. (Fig. 3775.) 



Aster foliaceus Lindl. in DC. Prodr. 5: 228. 1S35. 



Stem usually stout, sparingly pubescent iu 

 lines, 2°-3° high, branched above, the branches 

 ascending. Leaves rather thin, oblong-lanceo- 

 late, acute at the apex, entire, or with a few small 

 distant teeth, glabrous on both sides, very rough- 

 margined, 2'-4' long, Yi'-i' wide, the upper all 

 strongly clasping at the base, the lowest petioled; 

 heads corymbose-paniculate, numerous,! 'broad or 

 more; involucre hemispheric, its bracts green, folia- 

 ceous, oblong, mucronate, the inner mostly nar- 

 rower and acute; rays about 30, violet, \"-S" long; 

 pappus nearly white; achenes pubescent. 



Kimball Co., Nebraska (Rydberg). August. Asrec- 

 ognized by Dr. Gray, this species comprises several 

 varieties, widely distributed in the Rocky Mountains 

 and extending west to the Pacific. Our description 

 and figure are drawn from Mr. Rydberg's specimens. 



42. Aster sericeus Vent. Western 

 Silvery or Silky Aster. (Fig. 3776.) 



Aster sericeus Vent. Hort. Cels, pi. jj. 1800. 

 Aster argenteus Michx. FI. Bor. Am. 2: ill. 1803. 



Stem slender, paniculately or corymbosely 

 branched, stiff, glabrous, leafy, i°-2° high. Stem 

 leaves sessile, with a broad base, oblong, entire, 

 mucronate, '/i'-'iyi' long, 2"-5" wide, erect or as- 

 cending, with a dense silvery-white silky pubes- 

 cence on both sides; basal and lowest leaves 

 oblanceolate, narrowed into margined petioles; 

 heads numerous, about i^' broad; involucre turbi- 

 nate, its bracts oblong, or the inner lanceolate, 

 canescent, imbricated in 3 or 4 series, their tips 

 green, acute, spreading; rays 15-25, violet-blue, 

 6"-8" long; pappus tawny; achenes glabrous. 



In dry open soil, Illinois to Minnesota and Mani- 

 toba, south to Tennessee, Missouri and Texas. Aug.- 

 Sept. 



