388 FOUNDATIONS OF BOTANY 



and field-garlic are only a few of the many examples of 

 very troublesome weeds which were at first planted for 

 use or for ornament. 



456. Study of Weeds. Select two or more out of the 

 following list of weeds and report on the qualities which 

 make them troublesome from the farmer's point of view 

 (successful from their own). 1 



LIST OF WEEDS 2 



1. Barn-grass,* Panicum Crus-galli. 



2. Beggar's lice,* Cynoglossum officinale. 



3. Beggar's-ticks, Bidens frondosa. 



4. Black mustard,* Brassica nigra. 



5. Blue thistle,* Echium vulgare. 



6. Buffalo bur, Solarium rostratum. 



7. Burdock,* Arctium Lappa. 



8. Buttercup,* Ranunculus bulbosus. 



9. Butterweed,* Erigeron canadensis. 



10. Carpet weed, Mollugo verticillata. 



11. Charlock,* Brassica Sinapistrum. 



12. Chess or cheat,* Bromus secalinus. 



13. Chickweed, Stellaria media. 



14. Chicory,* Cichorium Intybus. 



15. Clover dodder,* Cuscuta Trifolii. 



16. Cocklebur,* XantJiium spinosum. 



17. Corn cockle,* Agrostemma Giihago. 



1 This study will be of little value in city schools, since the plants should 

 be examined as they grow. Specimens of the mature weed and of its fruits 

 and seeds may be preserved by the teacher from one season to another for 

 class use. Whole specimens of small plants, such as purslane, may be put 

 into preservative fluid (see Handbook). Ordinary weeds, such as ragweed, 

 pigweed, etc., may be pressed and kept as roughly prepared herbarium 

 specimens, while such very large plants as jimson weed, dock, etc., may be 

 hung up by the roots and thus dried. 



2 Names marked in the list thus * are those of plants introduced from 

 other countries, mostly from Europe. 



