420 ORDER 70. COMPOSITE. 



very silky; pappus simple. 2 Herbs with alternate Ivs. and close 

 corymbs. " Rays white. 



" S. Bolidagineus Nees. Smooth; Ivs. linear-ollanceolate, obtuse, entire, sessile, 

 obsoletely 3-veined, rough on the margin ; corymb fastigiate ; hds. aggregate, 

 subsessile, 5-rayecl ; scales obtuse, white, with green tips ; pappus white. In 

 woods, Can to La. Very elegant. Sts. clustered, slender, simple, about 2f high. 

 Lvs. smooth, 1 to 2' by 3 to 5". Hds. small (3" long). InvoT. oblong. Scales with 

 conspicuous green tips. Rays long, white. Jl., Aug. (Aster solidaginoidee MX.) 



2 L. coiryzoides Nees. St. somewhat pubescent, simple, corymbus at top; Ivs- 

 oval-lanceolate, smooth beneath, slightly 3-veined, narrowed at base, acute, the 

 upper ones sessile, nearly entire, the lower narrowed into the petiole, serrate ; in- 

 vol. cylindrical, the scales oval, obtuse, appressed, slightly reflexed at summit ; 

 rays 5, short, pappus rusty. Common in woods and thickets, Mass to Flor. 

 Stems somewhat 5-angled, 1 2f high. Leaves somewhat fleshy. Ray short, 

 but longer than the disk, white. July, Aug. (Aster Willd. Conyza aster- 

 oides L.) 



3 S. tortifolius Noes. Grayish-pubescent, roughish, corymbous above ; Ivs. 

 short, oblong-obovate, sessile, twisted to a vertical position, and both sides alike 

 minutely scabrous ; scales regularly imbricated in many rows, the green tips 

 slightly spreading ; pappus white. Dry woods and barrens, Ya. to Fla. and La. 

 Height about 2f, often branched below. Lvs. 8 to 12" long, obtuse or acute. Hds, 

 larger than in the others, about 5" long. Sept., Oct. 



18. AS V TER, L. (Gr. acrrr/p, a star ; from the radiated flowers.) Hds. 

 radiato ; involucre oblong, imbricate ; scales loose, often with green 

 tips, the outer spreading; disk flowers tubular, ; ray flowers $ , in one 

 row, generally few (6 100), ligulate, oblong, 3-tootlicd at apex, finally 

 revolutc ; receptacle flat, alveolate ; pappus simple, capillary, scabrous ; 

 achenium usually compressed. A large genus of 2 herbs, very abun- 

 dant in the U. S., flowering in late summer and autumn. Lvs. alter- 

 nate. Disk fls. yellow, changing to purple, ray flowers blue, purple or 

 white, never yellow. 



BIOTIA, DC. Scales closely imbricated, slightly tipped with green, lids, corymbous, 



rays 6 to 15, white or roseate. Lvs. cordate, petiolate, serrate, large Nos. 1, 2 



CALLIASTRUM, T. & G. Scales loosely imbricated, with green spreading tips. Heads 

 corymbous or few, large, rays 12 to 30, violet. Leaves never cordate, rigid ; pappus 



unequal, rigid, the inner slightly club-shaped. Leaves all or the lower serrate Nos. 3 5 



Leaves entire Nos. C, 7 



ASTER proper. Scales (variously) imbricated, with green tips or wholly green. Hds. 

 paniculate or racemous. Pappus soft, equal (none club-shaped), (a) 

 a Leaves clasping with a cordate or auriculate bnse. (b) 

 a Leaves sessile or pctiolate, none of them cordate or auricnlate. (c) 



a Leaves petiolate, the lower cordate, evidently serrate ..Nos. 8, 9 



entire or obscurely serrate Nos. 10 12 



b Leaves entire, very small (1 to 8" Ions), erect or reflexed Nos. 13, 14 



middle size (I to 8' long), Achenia silky Nos. 15 IT 



Achenia smooth Nos. 20, 35 



b Leaves serrate (more or less). Scales spreading, equal, in 2 rows No. IS 



Scales imbricated, in 3 to 5 rows Nos. 1921 



C Leaves silky on both sides alike. Pappus tawny ". Nos. 22, 23 



C Leaves not silky. Involucre closely imbricated, (d) 



Involucre squarrous, the scales spreading, (e) 



d Leaves all entire. Scales of the involucre obtuse Nos. 24, 25 



Scales acute or mncronate Nos. 2C 28 



d Leaves (lower) sharply serrate. Heads larger (4 to 6" long) Nos. 29, 30 



Heads small (2 to 3" long) Nos. 81, 82 



e Scales obtuse, in several rows, unequal. Leaves also obtuse. .Nos. 33, 34 



e Scales acute, in several rows, unequal. Pappus tawny Nos. 35 37 



Pappus bright Nos. 8840 



e Scales acute, in one row, equal. Leaves linear. Heads solitary.. -No. 41 

 SCARIOS^E. Scales (variously) imbricated, with scarious margins and destitute of 



f Leaves lanceolate broadly or narrowly. Scales rather obtuse Nos. 42 44 



Leaves subulate or linear. Scales very acute Heads large, few Nos. 45, 46 



Heads small, many Nos. 47, 48 



