COMPOSITE 



633 



Basal leaves broad, spatulate, oval to roundish, always rounded at the tip. 

 Leaves deeply cut on the edges, L. saliva var. intybacea (cutting or cut- 

 leaved lettuce). 

 Leaves entire or but slightly toothed. 



Leaves forming a rather compact roundish or flattish head; leaves never 

 decidedly stiff and flat, L. saliva var. capilala (head or cabbage lettuce). 

 Leaves forming a conical or cylindrical-shaped head; leaves straight and 

 stiff, L. saliva var. romana (cos lettuce). 



Jtule 

 branches 



anther tube 

 Corolla 



■pappus 



ovary 



Fig. 260. — Single flower of salsify (Tragopogon porrif olius) . X 2H- 



Tracy classifies the American varieties of lettuce as fol- 

 lows: (i) butter varieties, (2) crisp varieties, and (3) cos 

 varieties. These three groups are further subdivided. 



TRAGOPOGON PORRIFOLIUS (Salsify or "Oyster Plant") 



Description. — Salsify is a hardy perennial plant from a 

 fleshy root. The roots are about 12 inches long with a 

 diameter of about 2 inches at the top; the skin is grayish 

 white. The stems are usually somewhat branched and succu- 

 lent. When grown from seed, a seed stalk is sent up the 

 second season to a height of 2 to 4 feet. The leaves are alter- 

 nate, entire, linear-lanceolate, clasping at the base, and glau- 

 cous. Heads (Fig. 259) are single at the end of rather long, 

 thickened peduncles, which are often hollow for several 



