420 Oeder TO.—OOMPOSITjE. 



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

 corymbs. Rays white. 



"■ S. solidagineus Nees. Smooth; Ivs. Unear-obkmceolate, oliuse, eniire, SGsgiie, 

 obsoletely 3-veined, rough on the margin ; corymb faatigiate ; lids, aggregate, 

 subsessile, 5-rayed ; scales obtuse, white, with green tips ; pappus whiie. — In 

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

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

 conspicuous green tips. Kays long, white. Jl., Aug. (Aster solidaginoides Mx.) 



2 li. conyzoides Nees. St. somewhat pubescent, simple, corymbus at top ; lvs- 

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

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

 voL cylindrical, the scales oval, obtuse, approssed, slightly reflezed at summit ; 

 rays 6, short, pappus rusty. — Common in woods and thickets, Mass to Flor. 

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

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

 oides L.) 



3 S. tortifdlius Nees. Grayish-pubescent, roughish, corymbous above ; ha. 

 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, Ta. 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. 



i8. ASTER, L. (Gr. aarrip, a star ; from the radiated flowers.) Hdi=. 

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

 tips, the outer spreading ; disk flowers tubular, <i ; ray flowers § , in one 

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

 revolute ; receptacle flat^ alveolate ; j^appus simple, capillary, scabrous ; 

 achenium usually compressed. — A large genus of 71 herbs, very abun- 

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

 nate. Disk fls. yellow, changing to purple, ray flowers blue, purple i-'r 

 white, never yellow. 



§ EiOTiA, DC. Scales closely imbricated, eligbtly tipped with gi-een. Hds. corymbons, 



rays Gto 15, wiiite or roseate. Lvs. cordate, petiolate, serrate, large Nos. 1, 2 



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

 corymbous or few, large, rays 13 to SO, violet. Loaves never cordate, rigid ; pappus 



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



— Leaves entire Nos. 6, 7 



§ Aster proper. Scales (variously) imbricated, with green tips or wholly groon. Hds. 

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

 a Leaves clasping with a cordate or auriculate base., (b) 

 a Leaves sessile or petiolate, none of them cordate or auriculate. (e) 



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



— entire or obscurely serrate Nos. 10 — 12 



b Leaves entire,— very small (1 to 8" long), erect or retlexcd Nos. 18, 14 



—middle size (1 to 8' long),- Achenia sillcy Nos. 16—17 



— Achenia smooth Nos. 20, 85 



b Leaves serrate (more or less).— Scales spreading, equal, in 2 rows No. 18 



—Scales imbricated, in 8 to 5 rows Nos. 19—21 



C Leaves silky on both sides alike. Pappus tawjiy Kos. 22. 2.1 



C Leaves not silky. — tnvolncre closely imbricated, (d) 



— Involucre squarrous, the scales spreading, (e) 



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



— Scales acute or mucronate Nos. 2<1 — 2ft 



d Leaves (lower) sharply serrate. — Ileads larger (4 to &' long) Nos. 29, 80 



— Ueads small (2 to 8" long) Nos. 81, 82 



Scales obtuse, in several rows, unequal. Leaves also obtuse. .Nos. 8.8, 34 



e Scales acute, in several rows, unequal Pappus tawny Nos. 85—87 



—Pappus bright ..... .Nos. 88—40 



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

 S SoAEios.!!. Scales (variously) imbricated, with scarions margins and destitute of 

 green tips, (f) 



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



Leaves subulate or linear. Soalos very oeute.- Heads huge, few Nos. A ** 



— Heads small, many Nos. 47, 48 



