148 



FAM. 173. 



lar depressions; heads numerous, 4-7 flowered, rays 1-3; bracts 



in few rows; pappus brownish, _-__-_ Chrysomat 



C. (Solidago). pauciflosculosa. Viscid. Low sandy soil. Fall. 

 21. Ray-flowers few, about 5; — herbs with alternate, entire or toothed 

 leaves; heads 12-15 flowered, corymbose; bracts leathery in 

 few rows; disk yellowish or purplish, rays white or pink; pap- 

 pus of numerous scabrous bristles, ----- Sericocarpus 



S. bifoliatus (tortifolius). Stem grayish-pubescent, leaves obovate, short, ses- 

 sile; pappus white. Sandy pine barrens. Summer and Fall. 



21. Ray-flowers numerous, - - - - - - - - - 22* 



22. Bracts of the involucre in two rows; pappus of several short scales 



accompanied by 2-4 awns; — large smooth herbs with alternate, 

 narrow, sessile leaves; heads numerous, receptacle convex or 

 conical. Fall. - - ______ Boltonia 



B. diffusa. Stem slender, much branched; rays white. Low ground. 

 22. Bracts of the involucre in 3-5 rows; pappus of a single row of bris- 

 tles; — herbs with alternate leaves; the radiate heads collected in 

 corymbs, racemes or panicles, surrounded by an involucre of 

 imbricated bracts in several rows; receptacle flat or convex, 

 sometimes fimbrillate; disk-flowers yellow, changing to red, 

 brown or purple; rays white, pink, purple, blue or violet; pappus 

 in 1, rarely 2, series, bristly. Late Summer and Fall. _ Aster 



a. Basal and lower cauline leaves relatively narrow, with the base 

 contracted into a petiole; upper cauline leaves sessile or clasp- 

 ing; — stem trailing, usually pubescent; leaves short, entire, 

 elliptic to lanceolate, broadly clasping; heads solitary or clus- 

 tered at the ends of the leafy branches; bracts narrow, with 

 spreading or recurved dark-green tips; rays pale purple or pink. 

 Swamps. _-___-__ A. Carolinianus 



a. Cauline leaves merely sessile, --------b 



b. Leaves not fleshy, _--__-----c 



b. Leaves fleshy; — scattered, linear, those of the branches scale- 



like; heads few, terminal; bracts green on the back or at the 

 tips, imbricated in 5 rows; pappus tawny; rays purple to near- 

 ly white. Salt marshes. ------ A. tenuifolius 



c. Rays purple, lilac or violet, ___-_---<_ 



c. Rays pale-purple or white -_-_----e 



d. Leaves silky or canescent; heads in a raceme; — leaves oblong 



to linear, sessile; bracts linear, appressed, and like the leaves 

 grayish- white, in 4-5 rows, with green tips; pappus tawny; 

 rays 10-15, lilac. Sandy soil. ------ A. concolor 



d. Leaves rough, adnate to the stem and branches; heads small, 

 few, scattered, terminating the scaly branches; — basal leaves 

 obovate, few; cauline leaves small, oblong to lanceolate, num- 

 erous; bracts linear with dark-green tips; rays violet. Dry 

 pine land. --------- A. adnatus 



d. Leaves rough, more or less reflexed; heads small, few, scattered, 



terminating the scaly branches; — basal leaves spatulate, the 

 cauline rigid, oblong to ovate, ciliate; bracts with dark-green 

 tips; rays 14-24. Dry pine land. - - - - A. squarrosus 



e. Heads numerous, terminating slender branchlets; — stem smooth, 



paniculately branched; basal leaves spatulate, stem-leaves 

 linear or linear-lanceolate, often reflexed; those of the branches 



