198 



ELEMENTS OF BOTANY. 



239. 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).i 



List of Weeds.^ 



1 Tliis 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 

 (Appendix). Ordinary weeds, such as ragweed, pigweed, etc., maybe pressed and 

 kept as roughly prepared herbarium specimens, while such very large plants as 

 Jamestown weed, dock, etc., may be hung up by the roots and thus dried. 



2 The botanical names, as found in the last edition of Gray's Manual, are given 

 below. Names marked in the list thus * are those of plants introduced from other 

 countries, mostly from Europe. 



1. Oynoglossum oflBcinale. 



2. Desmodium Canadense ; Bidens fron- 



dosa. 



3. Arctium Lappa. 



4. Eanunculus bulbosus. 



5. Erigeron Canadensis. 



6. Xanthium spinosum, 



7. Brassiea Sinapistrum. 



8. Cichorium Intybus. 



9. Stellaria media. 



10. Chrysanthemum leucanthemum. 



11. Taraxacum otticinale. 



12. Rumex crispus. 



13. Anthemis Cotula. 



14. Setaria glauca. 



15. Solanum Carolinenae. 



16. Datura Stramonium. 



17. Malva rotundlfolia. 



18. Asclepias Cornuti. 



19. Urtica gracilis. 



20. Chenopodium album ; Amarantus 



retroflexus. 



21. Plantago major. 



22. Phytolacca decandra. 



23. Portulacca oleracea. 



24. Agropyrum repens. 



25. Ambrosia art emisise folia. 



26. Cenchrus tribuloides. 



27. Polygonum Hydropiper. 



28. Tauacetum vulgare. 



29. Cnicus lanceolatus ; Cnicus arvensis 



30. Achillea millefolium. 



