ORDER 70. ASTERWORT3. fc4] 



d Stem leaves c.asping, with a cordate or auricled base. . . .e 



d Stem leaves sessile, rarely clasping, never cordate or auricled .... 1 9 



e Involucre scales close, in several rows, outer ones gradually shorter. . . .8, 



e Involucre scales loose, nearly equal, outer ones often wholly green 10-12 



f Leaves lanceolate and linear-lanceolate, more or less rough 13-15 



f Leaves linear, fleshy, very smooth, entire. Salt-marsh herbs 16-18 



1 A. corymbo'sus. Corymbed S. Slender, with thin, serrate leaves. 



2 A. macrophyl'lus. Big-lvd. S. Stout, with large, thick, ser., rough Ivs. 18-rayed. 



8 A. cordifo'lius. Heart-leaved S. Involucre scales close, obtuse. Lvs. sharp-serrate. 

 4 A. sagittifo'lius. Arrow-leaved S. Scales awl-shaped, long, loose. Lvs. blunt-serrate. 



5 A. azu'reus. Azure S. Stem leaves sessile, rough, lanceolate, and lineal. 



6 A. undula'tus. Stem Ivs. on winged stalks, with rounded clasping bases, wavy. 



7 A. Shor'tii. Short's 8. Stem leaves on naked stalks, all cordate, pointed, entire. 

 ? A. patens. Patent S. Plant rough-downy. Leaves entire. Scales pointed. 



9 A. Isevis. Polished S. Plant smooth and glaucous. Scales broad, acute. 



10 A. prenanthoi'des. Lvs. sharply cut-serrate, with a long, slender, entire base. 



11 A. punic'eus. Eed-st. S. Lvs. sparingly serrate, lance. Stem hairy, often red. 



12 A. Novse-Anglise. New-England S. Leaves entire, rough, numerous. Raya 



nearly 100, J' long. Stems 4-6f. high. A fine species, often cultivated. 



13 A acnmina'tus. DM S. Leaves coarsely-toothed, broad-lanceolate, long-pointed, 



often clustered. Rays white. In dark woods. N. 



14 A. nemora'iis. Wood 8. Leaves narrow-lanceolate, nearly entire, acute, with 



edges revolute. Heads 1-3. In damp woods. N. M. 



15 A. ptarmicoi'des. Sneezewort S. Leaves entire, stiff, acute. Heads corymbed. 



16 A. flexuo'sus. Zigzag S. Heads large, with showy rays. Stem flexuous. 



17 A. linifo'lius. Flax S. Heads numerous, with very short rays in 2 rows. 



18 A. subnla'tus. Heads with showy blue rays. Scales in 2 or 3 rows. S 

 19 Ma iy species, very variable, here omitted. (See p. 420, Class Book.) 



6. ERIG'ERON. Fleabaiie. Whiteweed. 



Heads many-flowered, mostly hemispherical, rays very numerous 

 (20-200), narrow, linear, pistillate ; disk flowers perfect. Receptacle flat, 

 naked (no chaff or pits). Scales of the involucre nearly equal and in one 

 row. Pappus generally simple. Herbs with alternate leaves. Rays 

 white, blue, or reddish. Flowering from May to September. 



Rays showy, longer than the involucre. Heads large (1-1' broad).... a 

 Rays obscure, shorter than the involucre, whitish. Heads very small. . . .1, 2 

 a Rays p.irple, very numerous. Heads loosely corymbed.. ..3-5 



a Rays white or whitish. Heads loosely panicled 6-8 



1 E. Canaden'se. Canada F. Erect, hairy. Leaves lanceolate. Heads panicled 

 9 E. divarica'tum Prostrate F. Low, diffuse. Lvs. linear. Heads corymbed. W 



