246 KEY AND FLORA 
at the apex; chaff as long as the flowers. Akenes oblong, the wings 
narrow and thickened; pappus of 2 minute teeth. In rich woods.* 
5. C. palmata Nutt. Srrer Tickseep. Perennial; stem stiff, 
smooth, little or not at all branched, very leafy, 1-3 ft. high. Leaves 
3-cleft, broadly wedge-shaped, stiff; the lobes linear-oblong, middle 
one often 3-lobed. Heads on short peduncles, few or solitary, 14-2 in. 
in diameter; bracts of the outer series narrower than the inner ones, 
slightly shorter. Rays 6-10, bright yellow, broad, usually 3-toothed. 
Akenes oblong, with narrow wings. Dry prairies and thickets W. 
6. C. verticillata L. Perennial; stem smooth, stiff, slender, branch- 
ing freely, leafy, 1-2 ft. high. Leaves divided into 5 sessile leaflets, 
the latter once or twice pinnately parted into narrowly linear or thread- 
like divisions. Heads 11-1} in. in diameter; outer bracts much nar- 
rower than the inner ones. Rays 6-10, yellow. Akenes oblong, with 
narrow wings. In dry or moist soil, sometimes cultivated. 
VII. HELENIUM L. 
Annual or perennial. Leaves alternate, forming wings on 
the stem. Heads radiate, peduncled, many-Howered; bracts in 
2 series, the outer linear and spreading, the inner few and 
seale-hke ; receptacle naked, convex or oblong. Ray flowers pis- 
tillate and fertile, or neutral, the rays wedge-shaped, 3-5-lobed; 
disk flowers bisexual, tubular, 4-5-lobed. Akenes top-shaped, 
hairy, ribbed; pappus of 4-5 entire, toothed or awned scales.* 
1. H. nudiflorum Nutt. Snerzewerp. Perennial; stem slender, 
erect, downy, branched above, 1-2 ft. high. Leaves lanceolate, entire 
or slightly toothed, the lower petioled, the upper sessile. Ifeads nu- 
merous. Ray flowers 10-15, neutral, yellow or yellow and brown; 
disk flowers purple. Akenes hairy on the ribs; pappus of ovate, 
minutely toothed, awned scales. Common on river banks § 
VIN. ACHILLEA L. 
Perennial. Leaves alternate, pinnately divided. Heads with 
ray flowers in a terminal corymb ; involueral bracts imbricated 
in several series, the outer shorter; receptacle chaffy. Ray 
flowers white or pink, pistillate and fertile; disk flowers bi- 
sexual, tubular, 5-lobed. Akenes oblong, compressed, slightly 
margined ; pappus none.* 
1. A. Millefolium L. Yarrow. Stems often clustered, erect from 
a creeping rootstock, simple, downy or woolly, 1-2 ft. high. Leaves 
