GENUS 31. 



THISTLE FAMILY. 



433 



Aster lutescens (Lindl.) T. & G. is a very interesting race with light yellow rays, known from 

 Illinois, Wisconsin and Saskatchewan. Yellow rays are otherwise almost or quite unknown in the 

 genus Aster as here limited. 



73. Aster tenuifolius L. Perennial Salt- 

 marsh Aster. Fig. 4354. 



Aster tenuifolius L. Sp. PI. 873. 1753. 

 Aster fle.ruosus Nutt. Gen. 2: 154. 1818. 



Perennial, glabrous and fleshy; stem flexuous, 

 striate, at least when dry, sparingly and loosely 

 branched, i-2 high. Stem leaves linear, entire, 

 acute, sessile or partly clasping at the base, the 

 lowest lanceolate-linear, 2'-6' long, 2"-3" wide, 

 those of the branches minute, bract-like, ap- 

 pressed; heads rather few, 6"-i2" broad, termi- 

 nating the branches ; involucre turbinate, about 

 4" high, its bracts lanceolate, acuminate or mu- 

 cronate, glabrous, green on the back or tip, ap- 

 pressed, imbricated in about 5 series, the outer 

 shorter; rays numerous, longer than the pappus, 

 pale purple or nearly white; pappus tawny; 

 achenes hispid-pubescent, 5-nerved. 



In salt marshes, coast of Massachusetts to Flor- 

 ida. Aug.-Oct. 



74. Aster exilis Ell. Slim Aster. Fig. 4355. 



Aster exilis Ell. Bot. S. C. & Ga. 2 : 344. 1824. 



Aster divaricatus T. & G. Fl. N. A. 2 : 163. 1841. Not L. 1753. 



Annual, glabrous, fleshy; stem slender, usually much 

 branched, the branches usually divergent. Leaves linear 

 to linear-lanceolate, i'-4' long, \"-2,\" wide, entire, sessile, 

 acute or acuminate, or the lowest narrowly oblong, 3" -4" 

 wide and petioled, those of the branches subulate; heads 

 numerous, panicled, about 5" broad; involucre campanu- 

 late, about 3" high, its bracts linear-subulate, appressed, 

 imbricated in 3 or 4 series ; rays purplish, about 2" long, 

 mostly fewer than the disk-flowers, longer than the pappus; 

 achenes somewhat pubescent. 



In moist or wet soil, especially in saline situations, Kansas to 

 Texas, South Carolina and Florida. Bahamas ; Cuba. Aug.-Oct. 



75. Aster subulatus Michx. Annual Salt- 

 marsh Aster. Fig. 4356. 



Aster subulatus Michx. Fl. Bor. Am. 2: in. 1803. 

 Aster linifolius T. & G. Fl. N. A. 2 : 162. 1841. Not 

 L. 1753- 



Annual, glabrous and fleshy; stem paniculately 

 branched, flexuous above, i-6 high, slightly an- 

 gled, sometimes i' in diameter at the base, but 

 usually smaller. Stem leaves linear-lanceolate, 

 acute, entire, sessile by abroad or slightly clasping 

 base, 2'-io' long, i"-8" wide, those of the branches 

 very small and subulate ; heads numerous, 3"-s" 

 broad ; involucre campanulate, or at length hemi- 

 spheric, 2" 3" high, its bracts linear-subulate, 

 green, imbricated in 3 or 4 series, the outer shorter ; 

 rays 20-30, purplish, scarcely exceeding the nearly 

 white pappus, more numerous than the disk- 

 flowers ; achenes compressed, minutely pubescent. 



In salt marshes, coast of New Brunswick to Flor- 

 ida. Also on salt lands Onondaga Lake, N. Y. Aug.- 

 Nov. 



28 



