230 THE FLORA. 



d Stem leaves clasping, with a cordate or aiirieled base e 



d Stem leaves sessile, rarely clasping, never cordate or auricled 19 



Involucre scales close, in several rows, outer ones gradually shorter 8, 9 



• 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. Corynibed S. Slender, with thin, serrate leaves. 



2 A. maoropliyl'lus. Big-l/nd. S. Stout, with large, thick, ser., rough Ivs, 13-rayed. 



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



4 A. sagittifo'lins. Arrow-leased S. Scales awl-shaped, long, loose. Lvs. bluut-sen'ate. 



5 A. azu'rens. Azure S. Stem leaves sessile, roughs lanceolate, afld linear. 



6 A. undtila'tus. Stem lvs. on winged stalks, with rounded clasping bases, wavy, 



I A. Shor'tii. SJwrt'e S. Stem leaves on naked stalks, all cordate, pointed, entire. 



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



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



10 A..prenanjli6i'des. Lvs. sharply cut-serrate, with a long, slender, entire base. 



II A. punic'ens. Jied-af. S. Lvs. sparingly serrate, lance. Stem hairy, often red. 

 12 A. WoviE-AnglisE. New-England S. Leaves entire, rough, numerous. Bays 



nearly 100, %i long. Stems 4^6f. high. A fine species, often cultivated. 

 13 A. aoumina'tus. Ddl S. Leaves coarsely-toothed, broad-lanceolate, long-pointed, 



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

 li A. nemora'lis. Wood S, Leaves narrow-lanceolate, nearly entire, acute, with 



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

 15 A. ptarmicoi'des. Sneesewort 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'tns. Heads with showy blue rays. Scales in 2 or 3 rows. S. 

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



6. ERIG'EROIT. Pleabane. .WTiiteweed. 



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. — Herhs with alternate leaves. Rays 

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



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



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



a Eays purple, very numerous. Heads loosely corymbed. . . .8-5 

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



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



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



