292 NATURAL HISTORY. 



of every conceivable shade of crimson, purple, red, 

 rarely yellow, blooming from July until arrested by the 

 frost. Dahlias are cultivated by dividing the tuberous 

 roots, o 



The Musk Thistle (Carduus nutans) has a branching 

 thorny stalk ; leaves much dentated, clothed with hairs. 

 and prickly ; heads roundish, ovoid, spiny ; florets mostly 

 reddish-purple. Grows in old waste fields or by road- 

 sides. The seeds form the favorite food of the Thistle 

 Finches. 2. Also called Canada Thistle. Native 

 of Europe. 



The Burdock (Articum lappa). Stem branching, 

 roughish ; leaves heart-shaped, ovate, petiolate, cobwebby 

 tomentose ; radical ones one to two feet long and very 

 broad ; florets reddish-purple, with bluish anthers ; flower 

 heads short and spiny. The root about two feet long 

 and proportionably thick, fleshy, slimy, and of a sweet- 

 ish-bitter taste, is used in a decoction for purifying the 

 blood. Native of Europe. Grows in waste lands, by 

 fences, etc., and is a most troublesome weed. 2. 



The Artichoke (Cinara scolymus). Leaves alternate, 

 thorny, and deeply serrate ; stalk two feet high, bearing 

 purple flowers ; root thick, fleshy, and somewhat bitter. 

 The receptacle, together with the fleshy bases of the 

 scales of the involucre, are boiled and eaten as asparagus, 

 the tubers at the roots, used instead of potatoes. Native 

 of all countries bordering on the Mediterranean ; culti- 

 vated farther north, but requires some care and a rich 

 soil. 2. 



Sun Flower (Helianthus annuus). Leaves heart- 

 shaped, cordate, triple-veined, denticulate, or slightly 

 toothed ; stalk often six or seven feet high ; flowers single- 

 rayed, nodding, large, and expanding ; disk flowers 



