248 WEEDS 



in Fig. 421, poison sumac in Fig. 422, and poison oak of the 

 Pacific coast in Fig. 423; these are poisonous to the touch. 

 The handsome red berries of the bittersweet 

 (Solanum Dulcamara, Fig. 424) are poisonous 

 if eaten; and it has poisonous relatives. 



REVIEW. Explain your understanding of a weed. 

 How may we classify weeds? What are the com- 

 monest kinds of weeds in your locality? What enables a plant to be an 

 habitual weed? Name some of the weed groups or associations. Name 

 the ways in which weeds may be controlled or eradicated on farms. On 

 lawns. What would you recommend to be done with weedy roadsides? 

 Are there laws in your state for the control of weeds? Are there 

 village or city ordinances on the subject where you live? What is 

 an herbicide? Name the poisonous plants that you know, or of which 

 you have heard. 



NOTE. Every class studying plants should learn the usual weeds 

 of the neighborhood, and should make herbarium specimens of them. 

 Discussions should be had of the weeds infesting the local crops, and 

 the reasons for them. The school should have a collection of weed 

 seeds in bottles, and it should study commercial samples of grain and 

 grass seeds. The U. S. Department of Agriculture and perhaps the 

 State Experiment Station may have bulletins to aid in such examina- 

 tion. If the school is to indentify weed seeds in such samples, it should 

 also have a collection in bottles of the leading grains, grass seeds and 

 field seeds. A small lens or. magnifier is needed for this examination, as 

 shown in Fig. 425, or in Figs. 214, 216. 



Many plants are poisonous to a greater or less degree. No one should 

 eat of any plant or fruit or root that he does not know to be safe. 

 Some plant families are known for poi.-jonous qualities: as Solanaceae, of 

 which the common black nightshade (Solanum nigrum) and others are 

 examples; Umbelliferse, with the hemlock herbs, water parsnip, and 

 others; Ranunculaceae, with the aconites or monkshoods; and other 

 families. Fatalities are frequently reported from eating the thick roots 

 of certain Umbelliferse. There are useful government publications on 

 poisonous plants. 



