MONOPETALOUS EXOGENOUS PLANTS. 323 



STOKESIA, L'ller. 



Heads many-flowered ; the marguuil flowers much 

 larger, deeply split on tb.e inside, and ray-like; involucre 

 subglobose, bracted, the outer scales prolonged into a leafy 

 bristly-fringed appendage, the inner ones lanceolate and 

 entire; receptacle naked; achenia short, 3-i-angled, 

 smooth ; j'jfl'j!?;;?^ 5 composed of 4-5 filiforni chaffy deciduous 

 scales. — A sparingly branched downy-stemmed perennial ; 

 leaves smooth, lanceolate, entire, the upper ones sessile, 

 and, like the bracts, fringed at the base, the lowest nar- 

 rowed into a slender petiole ; heads few or solitary, large, 

 terminal; flowers blue. 



S. CYANEA, L'Her. AYet pine-barrens. Stems 1°-!^° 

 high ; heads 1 ' wide. 



ELEPHANTOPUS, L. Elephant's-foot. 



Heads 3-5-flowered, crowded in terminal 3-bracted 

 clusters ; floiuers all equal and similar ; involucre com- 

 pressed ; scales 8, in 2 rows, dry, oblong, acute, dotted ; 

 receptacle naked ; corolla deeply split on one side, palmate ; 

 aclieniiun oblong, ribbed, hairy ; pappus bristly from a 

 dilated base, double or single. — Erect hairy corymbose- 

 branched perennials, Avith alternate ample leaves, and pur- 

 ple or white flowers. 



E. tomextosus, L. Rough-hairy; stem nearly naked; 

 radical leaves spreading, obovate-oblong, narrowed into a 

 petiole; stem-leaves (1-2) small, lanceolate; hracts ovate 

 or cordate, usually shorter than the heads ; scales of the 

 involucre very hairy. (E. nudicaulis. Ell.) Dry sandy 

 soil. Stem l°-2° high ; radical leaves 4-10' long, 2' wide, 

 spreading on the ground; floiuers pale purple. 



Tribe II. Eupatoriacese. Heads discoid; the floivers 

 all tubular and perfect ; branches of the style usually 

 elongated, club-shaped, minutely pubescent ; the stigmatic 

 lines obscure ; flowers white, blue, or purple. 



