370 ASTERACEAE. 



both tubular and radiate flowers. Involucre hemispheric 

 or campanulate, its bracts narrow, nearly equal, usu- 

 ally imbricated in but 1 or 2 series. Receptacle nearly 

 flat, usually naked. Ray-flowers purplish or whitish, 

 pistillate. Disk-flowers yellow, tubular, perfect, 5-lobed. 

 Style-appendages short, mostly rounded or obtuse. 

 Achenes flattened, mostly 2-nerved. Pappus-bristles 

 scabrous, in 1 series or with an outer shorter series. 



Rays 30-40, purple; leaves not soft-pubescent. 



Leaves narrowly oblanceolate, 4 mm. wide 



or more. 1. E. foliosus. 



Leaves linear-filiform, less than 2 mm. wide. 2. E. fragilis. 

 Rays 100 or more; leaves more or less soft- 

 pubescent. 



Plants corymbosely branched above; leaves 



serrate or coarsely toothed. 3. E. philadelphus. 



Plants diffusely branched from the base; at 



least the stem leaves entire. 4. E. divergens. 



L E. foliosus Nutt. Scabrous and somewhat strigose-pubes- 

 cent, 4-8 dm. high, leafy throughout; leaves narrowly oblanceolate, 

 entire, about 4 mm. broad, 3-6 cm. long, those of the branches 

 reduced; heads hemispheric, 12-14 mm. broad; ra^^s about 30, 

 narrow, purple; achenes with a few coarse bristly short hairs. 



Frequent in sandy soil toward the coast. 



2. E. fragilis Greene. Stems erect, rigid, 5-7 dm. high, minutely 

 scabrous, leafy; leaves linear-filiform, 3-5 cm. long, rigid, rough 

 with minute incurved hairs; heads usually 10-15, arranged in a 

 loose corymbose panicle on spreading branches; involucre campanu- 

 late, its bracts in about 3 series; rays 30-40, very narrow, deep 

 violet; achenes nearly glabrous. 



Frequent on the dry plains and foothills away from the coast. 



3. E. philadelphicus L. Perennial by stolons, soft-pubescent 

 or sometimes nearly glabrous; stems slender, mostly branched 

 above, 3-6 dm. high; lower leaves spatulate or obovate, obtuse, 

 dentate, 2.5-7 cm. long, narrowed into a short petiole; upper leaves 

 clasping, often cordate at base, entire or dentate; heads several or 

 many, corymbose-paniculate, 1-2 cm. broad; peduncles slender, 

 thickened at the summit; involucre depressed hemispheric; its bracts 

 linear, usually scarious-margined; rays 100-150, 4-8 mm. long, 

 light rose-purple; pappus simple; achenes puberulent. 



Occasional in low moist ground. 



4. E. divergens Torr. & Gray. Stems usually many from an 

 annual or biennial taproot, often decumbent at base; herbage 

 cinereous with a short hispid pubescence; basal leaves narrowly 

 spatulate, usually entire, the upper linear, 1-2 cm. long; heads 

 solitary, terminating slender peduncles; rays about 100, filiform, pale 

 purple or nearly white; inner pappus of scanty slender bristles, the 

 outer much shorter, subulate. 



