MOXOPETALOUS EXOGENOUS PLANTS. 325 



ing a loose spreading corymb ; i^ales linear ; 2)ap}ms 

 purplish. 



C. coRYMBOSUS, Torr. and Gray. Stem stout, erect, liairy, 

 single; leaves slightly hairy, obtuse, oblanceolate, tapering 

 at the base ; heads about 20, 20-flowered in a dense corymb- 

 ous cyme; scales smooth, oblong oval. Stem 3° high; 

 flowers purple. 



LIATEIS. Button Snakeroot. 



Heads few to many (5-60) flowered ; floicers all per- 

 fect, tubular ; involucre oblong imbricated ; receptacle 

 naked; pappus abundant and bristly; aclienia tapering to 

 a slender base; styles much exser ted.— Perennial lierls, 

 erect stems, alternate leaves ; flowers rose-color, sometimes 

 white. 



* Scales of the involucre colored, ayidpetioled at their ends. 



L. ELEGANS, Willd. Leaves glabrous, the radical oblan- 

 ceolate, 3-5-veined, cauline, linear, the upper bract-like, 

 spreading; spike or raceme dense; lieads oblong-cylindri- 

 cal, 4:-5-flowered ; scales of the involucre petal-like, pur- 

 ple ; stem tomentose. 



L. SQUARROSA. (BltM^iig Star.) Leaves linear, smooth 

 or scabrous-pubescent ; racemes flexuous, leafy ; heads few, 

 20-40-flowered, sessile or nearly so ; involucre ovate-cy- 

 lindrical ; scales large, squarrous-spreading, outer larger, 

 leafy, inner mucronate-acuminate, scarcely colored. 



** Heads Z-l-flowzred, in one-sided spikes or racemes ; pappus densely bearded. 



L. GRACILIS. Stem pubescent, slender, simple ; leaves 

 linear, 1 -veined, the lower lanceolate, obtuse, all glabrous, 

 ciliate at the base, long petioled ; heads 3-7-flowered on 

 divaricate, slender, hairy pedicels, in a long virgate ra- 

 ceme, rarely paniculate; scales few and appressed, shorter 



