230 FOUNDATIONS OF BOTANY 



on long, hairy-fringed petioles, the upper lanceolate, sessile. Heads 

 few, on long peduncles ; bracts ovate-lanceolate, the outer narrower. 

 Ray-flowers 6-10, rays 3-5-lobed, bright yellow. Akenes oval, 

 broadly winged, warty. Pappus of 2 teeth. On rich, dry soil S. 

 and E.* 



3. C. auriculata, L. RUNNING TICKSEED. Perennial; stem ascend- 

 ing or decumbent, weak, smooth, nearly simple, 6-15 in. long. 

 Leaves ovate to oval, entire or with 2-4 small and rounded lobes at 

 the base, downy, long-petioled. Heads 1-1^ in. wide, few or single ; 

 outer bracts narrower than the inner. Rays 6-10, mostly 4-toothed 

 at the apex ; chaff as long as the flowers. Akenes oblong, the wings 

 narrow and thickened. Pappus of 2 minute teeth. In rich woods.* 



IV. RUDBECKIA, L. 



Perennial 'or biennial. Leaves alternate, entire or lobed. 

 Heads radiate, long-peduncled, many-flowered; bracts imbri- 

 cated in 2-3 series, spreading ; receptacle convex or long-coni- 

 cal, with concave, chaffy scales. Ray -flowers yellow, neutral ; 

 disk-flowers purple to brown, perfect. Akenes smooth, 

 4-angled, truncate. Pappus a few short teeth or wanting. 1 * 



1. R. hirta, L. CONE-FLOWER. Annual or biennial ; stem erect, 

 rough-hairy, simple or branched, 2-3 ft. high. Leaves lanceolate to 

 oblong, thick, obscurely serrate, rough-hairy, 3-ribbed, the lower 

 petioled, the upper sessile. Heads few, long-peduncled ; bracts 

 rough-hairy, spreading. Ray-flowers 10-20, orange-yellow; disk- 

 flowers purplish brown. Chaff acute, hairy at the apex. Pappus 

 none. On dry, open ground. 



V. HELENIUM, L. 



Annual or perennial. Leaves alternate, forming wings on 

 the stem. Heads radiate, peduncled, many -flowered ; bracts 

 in 2 series, the outer linear and spreading, the inner few and 

 scale-like ; receptacle naked, convex or oblong. Ray-flowers 

 pistillate and fertile, or neutral, the rays wedge-shaped, 3-5- 

 lobed ; disk-flowers perfect, tubular, 4-5-lobed. Akenes top- 

 shaped, hairy, ribbed. Pappus of 4-5 entire, toothed or awned 

 scales.* 



1. H. nudiflorum, Nutt. SNEEZEWEED. Perennial; stem slender, 

 erect, downy, branched above, 1-2 ft. high. Leaves lanceolate, 

 entire or slightly toothed, the lower petioled, the upper sessile. 



