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-U 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. Kay -flowers yellow, neutral ; 

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

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



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-flow^ers 10-20, orange-yellow; disk- 

 flowers purplish brow^i. Chaff acute, hairy at the apex. Pappus 

 none. On dry, open gTOund. 



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. 



