230 THE FLORA. 



d Stem leaves clasping-, with a cordate or auricleJ base e 



d Stem leaves sessile, rarely claspinof, never cordate or auriclcd. . ..19 



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



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. macrophyrius. Big-lvd. S. Stout, with large, thick, ser., rough Ivs. 13-rayed. 

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

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



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



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



7 A. Shor'tii. SJiorfs S. Stem leaves on naked stalks, all cordate, pointed, entire. 



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



9 A. laevis. 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. Red-st. S. Lvs. sparingly serrate, lance. Stem hairy, often red. 



12 A. Novce-Angliae. Kew-England S. Leaves entire, rough, numerous. Kays 



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



13 A. acumina''tus. Pell S. Leaves coarsely-toothed, broad-lanceolate, long-pointed, 



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



14 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. Sneezewort S. Leaves entire, stiff, acute. Heads corymbed. 



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



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



18 A. subula'tus. 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'EROK Fleabane. 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 (i-V broad) a 



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



a Kays purple, 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. 



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



