188 COMPOSITE. 



1. A. ARVENSIS, L. Com Chamomile. 



Pubescent; leaves pinnately parted; diri.iions linear-lanceolate, toothed, very 

 acute ; branchlets leafless at the summit; involucre scales obtuse; chaff lancaolata, 

 pointed; achenia crowned with a very short margin. 



Fields and cultivated grounds. Introduced from Europe. June — Au^. Bienn'- 

 al. Stem 9 to 15 inches high, branched. Leaves grayish-pubescent. Heads large ; 

 rays broad, white, spreading-; disk yellow, convex. • 



2. A. nobilis, L. Garden Chamomile. 



Stem prostrate, branching from the base, wcolly ; leaves decompound-pinnatifid ; 

 segments linear-subulate; chaff with a thin membraneous margin, lanceolate, 

 scarcely as long as the flowers. Per. Native of Europe. Cultivated iu gardens 

 for its tonic and anodyne properties. The agreeable scent of the chamomile is well 

 known. 



39. ACHILLEA, Linn. Yarrow. 



So named because its virtues are said to have been discovered by Achilles. 



Heads many-flowered ; ray-flowers 4 to 6 pistillate, ligu- 

 late, short, or none ; disk-flowers perfect, tubular 5-toothed. 

 Receptacle chaffy, flattish. Achenia oblong, flattened, 

 margined. Pappus none. — Perennial herbs, with much di- 

 vided alternate leaves and Small corymbose heads of whitish flowers. 



1. A. Millefolium, L. Common Yarrow. Milfoil. 



Stems mostly simple, erect, somewhat hairy; leaves twicc-pinnately parted; the 

 divisions linear, 3 to 5 cleft, crowded ; corymb compound, flat-topped; involucre ob- 

 long; receptacle small. 



Fields and hills; common. Aug. Stem 1 to 2 feet high, branched at the top. 

 Leaves 2 to 6 inches long, cut into very numerous narrow segments. Beads nu- 

 merous, in a densa terminal fastigiate corymb; ruys i to 5, short, white or rose-col- 

 ored. 



40. LEUCANTHEMUM. Toura. Ox-eye Daisy. 



Gr. leulcos, white, and anthzmon, a flower. 



Heads many-flowered; ray-flowers numerous, fertile, or 

 rarely neutral ; disk-flowers perfect, with a fleshy somewhat 

 2-winged tube. Involucre broad and flat, imbricated; 

 scales with scarious: margins. Receptacle naked, flat or 

 convex. Achenia of the disk and ray similar, striate, des- 

 titute of pappus. — Perennial herbs, with toothed or pinnati- 

 Jid, alternate leaves and large single heads ) with white rays and y el* 

 low disk terminating the branches. 



1. L. vulGare, Lam. Ox-eye. White Daisy. White- 

 weed. 



Stem erect, nearly simple, naked above; root-leaves spatulate, petioled, toothed; 

 stem.*" eaves somewhat claspiug, cut or piunatifid-toothed ; involucre scales with a 

 narrow rusty brown margin. 



A pernicious weed, extensively naturalized in fields and meadows. June — Aug. 

 ,Stei» 1 to 2 feet high, erect or subnlecunibent at base, smoothi6h. Leaves compar- 



