114 



WEEDS, AND THE MANAGEMENT OP THEM 



Fig. 152. 

 Burdock {Lappa Tnajor). 



to ask to what state our agriculture would probably have attained at this time if it had not been for 

 weeds. There is no danger, however, that we shall cease to be taught. 



Poisonous plants. 



Certain plants are poisonous either when eaten or when handled. The most 

 deadly of the poisonous plants are some of the mushrooms (which see, in Part 

 III), and the water parsnip (Fig. 167) and poison hemlock (Fig. 168). The last 

 two are rank-smelling, strong herbs, members of the parsnip family (Umbellif- 

 era), inhabiting wet places. V. K. Chesnut in "Thirty Poisonous Plants of 

 the United States" (Farmers' Bulletin No. 86, United States Department of 

 Agriculture), writes as follows: The musquash-root, or water hemlock (Cieuta 

 maeulata) "is one of the most poisonous native plants in the United States, 

 being rapidly fatal to both man and animals. The roots are especially dan- 

 gerous, because the taste, being aro- 

 matic and to some people suggesting 

 that of horse-radish, parsnips, artichokes, or sweet cicely, is 

 apt to lead children to eat them when they are found forced 

 out of the soil by washing, freezing, or other causes in early 

 spring." The poison hemlock (Conium maculatum) contains 

 "the well-known volatile alkaloid, coniiie, which is found in 

 the seeds, and, especially at flowering time, in the leaves. The 

 root is nearly harmless in March, April and May, but is dan- 

 gerous afterwards, especially during the first year of its 

 growth. The poison hemlock is the most generally known 

 poisonous plant historically, it being, 

 without much doubt, the plant ad- 

 ministered by the Greeks 

 to Socrates and other state 

 prisoners. Recent cases of 

 poisoning have arisen ac- 

 cidentally from eating the 

 seed for that of anise, the 

 leaves for parsley, or the 



roots for parsnips ; also, from blowing whistles made from the hollow stems. 

 It has recently been shown that some of the anise seed in both foreign and 

 domestic markets is contaminated with hemlock seeds, but it is not known 

 whether serious consequences have resulted therefrom." The only other 

 poisonous plants or weeds that need be mentioned here are two or three spe- 

 cies of the sumac genus: Rhus Toxicodendron, the poison ivy (Fig. 169); R. 

 diversiloba, the poison oak of the Pacific coast (Fig. 170); R. venenata, the 

 poison sumac (Fig. 171), an attractive bush growing in swamps. These are 

 poisonous to the touch to many persons. It is enough for the present purpose 

 merely to identify them by means of pictures. Poisoning by ivy and sumac is treated with a solution of 

 sugar of lead (poisonous if taken internally), in 50 to 75 per cent alcohol. Add the sugar of lead "until 

 no more will easily dissolve. The milky fluid should then be well rubbed into the aifected skin, and the 

 operation repeated several times during the course of a few days." There are a number of plants that 

 are poisonous to live-stock, and these will be treated in Vol. Ill ; and there are others that have 

 medicinal qualities, and these are mentioned in Part III of the present volume. 



Fig. 154. 



Mallow or ' ' Cheeses ' ' (Malva rotundilolia) . 

 Biennial or perennial. 



Fig. 153. Mullein {Terhas- 

 cum Thapsua). 



Fig. 155. Bindweed (Convolvulus arvensit). 



