542 COMPOSITAE (COMPOSITE FAMILY) 



panicle at the summit of the stalk and on short axillary branches ; 

 pale yellow, each less than a. half-inch broad, on very short 

 pedicels ; beginning at the top, they open a few at a time, daily. 

 Achenes brown, ridged lengthwise, with thread-like beak and 

 pappus of fine, white, silken hair. (Fig. 374.) 



Not quite so obnoxious nor so common as the variety just de- 

 scribed, but still a very bad weed, is the True Prickly Lettuce (L. 

 scariola, L.) differing chiefly in that its prickly ribbed leaves are 

 lobed or pinnatifid, and the smooth or sparsely prickled woody 

 stalk usually taller ; the heads are similar but slightly smaller, very 

 numerous. The plant ranges from New England and Pennsylvania 

 westward to Michigan and Missouri. (Fig. 375.) 



Means of control 



Deep cutting of the tufted root-leaves, well below the crown, 

 with hoe or spud ; cutting of flowering stalks at the beginning of 

 bloom or earlier. In a grain field, hand-pulling of the young 

 flower-stalks before bloom will be a paying operation, as the crop 

 will not be worth much if the weed is allowed to absorb the fertility 

 and moisture of the soil. Rankly infested ground should be put 

 under cultivation for the purpose of stirring dormant seed into life 

 and destroying the seedlings. Sheep and young cattle graze the 

 young plants freely and prove good assistants in keeping the weed 

 in check, but milch cows must not have much of it as the juices 

 are bitter and will taint the milk. Seeds are widely wind-sown, and 

 it is to the interest of the entire community to see that none are 

 allowed to mature in roadsides and waste places. 



WILD LETTUCE 

 Lactuca canadensis, L. 



Other English names: Wild Opium, Horseweed, Trumpet Milkweed. 

 ^Native. Annual and winter annual. Propagates by seeds. 

 Time of bloom : June to October. 

 Seed-time: July to November. 

 Range: Nova* Scotia to the Northwest Territory, southward to 



Georgia, Alabama, Louisiana, and Arkansas. 

 Habitat: Fields, meadows, roadsides, and waste places. 



