420 Ordbe to.— composite. 



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

 corymbs. 'Eays white. 



" S. solidagmeus Nees. Smooth; his. Unear-oUamceolaie, obtuse, entire, sessile, 

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

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

 woods, Can to La, Tery elegant. Sta. clustered, slender, simple, about 2f high. 

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

 conspicuous green tips". Eays long, white. Jl., Aug. (Aster solidaginoides Mi.) 



2 L. oonyzoides Nees. St. somewhat pubescent, simple, corymbus at top; lvs- 

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

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

 vol. cylindrical, the scales oval, obtuse, appressed, sUghtly reflezed 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 Willcl;. Conyza aster- 

 oides L.) 



3 S. tortifolius Nees. Grayish-pubescent, roughish, corymboua above; hs. 

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

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

 slightly spreading ; pappiis 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. 



18. AS^TER, L. (Gr. aarrip, a star ; from the radiated flowers.) Hds. 

 radiate ; 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-toothed at apex, finally 

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

 achenium usually compressed. — A large genus of 2f 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 or 

 white, never yellow. 



§ BiOTiA, DO. Scales closely imbricated, slightly tipped with green. Hds. corymbons, 



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



§ Calhabtrum, T. & G. Scales loosely imbricated, with green spreading Jips. Heads 

 corymbous or few, large, rays 32 to 30, violet Leaves never cordate, rigid ; pappus 



unequal, rigid, the inner slightly club-shaped. — Leaves all or the lower serrate Nos. 8 — 5 



— Leaves entire No3. '6, 7 



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

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

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

 a Leaves sessile or petiolate, none of them cordate or auriculate. (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" long), erect orreflexed Nos. 18, 14 



—middle size (1 to 8' long), — Achenia silky Nos. 15—17 



— Achenia smooth Nos. 20, 35 



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



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



C Leaves silky on both sides alike. Pappus fcaivny Nos. 32, 23 



c Leaves not silky. — Involucre closely imbricated, (d) 



— Involucre squarrous, the scales spreading, (e) 



d Leaves all entire.— Scales of the involucre obtuse ^'"- ^^ j2 



— Scales acute ov mucronate Nos. 2C— 28 



d Leaves (lower) sharply serrate.-Heads larger (4 to 6" long) Nos. 29, 80 



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



e Scales obtuse, in several rows, unequal. Leaves also obtuse. .Nos. 88, 84 



e Scales acute, in several rows, unequal. — Pappus tawny Nos. 85 — 8T 



—Pappus bright Nos. 88-40 



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

 '5 SoABioSvB, Scales (variously) Imbricated, wltli scarious margins and destitute of 

 green tips, (f) 



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



Leaves subulate or linear. Scales very acute.— Heads large, few Nos. A *° 



—Heads small, many Nos. 47, 48 



