WEEDS OF THE cillcoKV FAMILY. 



i r 



from Europe, reaching Massachusetts aboul L863 and [ndiana in 



1884, since which time it lias spread over the entire State. Each 

 plant produces from 8,000 to 10,000 seeds, which by aid of the 

 abundant pappus are wafted far and wide by vxwy passing breeze, 

 and are ready to sprout and grow wherever and whenever the 

 proper conditions of soil, moisture and temperature are present. 

 The numerous prickles and bitter milky juice prevent all animals 

 but sheep from feeding upon it. They eat it, especially the young 

 leaves, greedily and in pastures it can be kept down by them alone. 

 Its most aggressive character is its ability to grow anywhere and 

 everywhere that its seed can secure a covering of earth and so 

 from crevices in gutters into which a little soil has drifted, "from 

 stone heaps, weed-choked corners of fences and yards, roadways 

 and beaten paths it flourishes. But such poverty and ill usage are 

 by no means essential factors to its success, for it also springs up 

 in gardens, meadows and cultivated fields. Still the power .to ex- 

 tract sufficient moisture and food from compacted and sunbeaten 

 earth, and thus to overtop competitors, and in the less favorable 



spots to grow where few plants could live, 

 place it in the front rank of noxious an- 

 nual weeds."* Remedies: repeated mow- 

 ing before the seeds ripen ; burning ma- 

 ture plants; thorough cultivation. 



A closely allied species, the "strong 

 scented lettuce" (L. virosa L., Fig. 107), 

 is very common in clover fields. It dif- 

 fers in having the leaves all entire and 

 lanceolate, the prickles on midribs and 

 edges shorter, and also in being a winter 

 annual, springing from the seed in au- 

 tumn and reaching maturity in May or 

 June of the next season. Both plants 

 when cut or broken stool freely, sending 

 up numerous spreading branches from 

 the lower part, so that they must be cut 

 with a hoe or pulled to prevent the ripen- 

 Both are "compass 

 plants," having the leaves twisted on the 

 stem so that their edges point up and down or vertical instead of 

 horizontal, and the ends for the most part point north and south. 

 The larger area of the leaves is therefore toward the east and west. 



•J. ('. Arthur, Bull. 52, Purd. Univ. Agr. Exp. Sta., 103. 



Fig. 107. Showing the fruit with 

 bristly parachute-like pappus at end of a \i\cr of tllC Seeds 

 long beak; a head of ripe fruits and a 

 head of flowers. (After Atkinson.) 



