COMPOS1TAE (COMPOSITE FAMILY) 



541 



Stem erect, with short lateral branches, round, smooth except 

 for a few prickles near the base, sometimes attaining a height of 

 seven feet but usually two to five feet tall ; occasionally it has a 

 purplish tinge. Leaves alternate, light green, oblong, variable, often 

 obtuse at tips but sometimes acute, with wavy, prickly-toothed 



Fio. 374. Prickly Lettuce 

 (Lactuca scariola, var. integrata). 



FIQ. 375. True Prickly 

 Lettuce (Lactuca scariola). 



xi 



edges and thick, whitish green midrib, closely set with spines on 

 the under side, sessile, clasping, auricled at base. Leaves of plants 

 growing in the open have a vertical twist at the base which causes 

 their edges to point north and south ; plants growing in the shade 

 have not this twist to the leaves. Heads numerous, in a large 



