In the contest with weeds, the farmer should dis tinguish the kinds as to duration. It is obviously one problem to deal with perennials and another problem to deal with annuals. In the annuals, it is necessary only to prevent seeding, so far as dissemi nation or persistence is concerned. In perennials, it mac be necessary to destroy or crowd out the entire plant, root and all. In grass lands, the annuals perish as a matter of course; or, if they do not, it is because the grass is poor. The annual weeds follow tilled crops; among such are the pigweeds, purslane, chess, ragweed. The perennials that follow cultivated crops are mostly such as have root stocks or other underground parts that are car ried by the tools; as bindweed, quack-grass and nut-grass. The weeds of dooryards are mostly perennial or, at least, biennial, as docks, bur dock, plantains, self-heal, round-leaved mallow. In the accompanying pictures, Figs. 134 to 148 show annuals; Figs. 149 to 154 biennials; Figs. 155 to 171 perennials.
Whenever any area becomes badly infested with weeds, it is safe to assume that the place should be given a radical change of treatment. Areas long used for garden are likely to become very weedy: seed down the place and make the garden somewhere else for a time. A patch of Canada thistles can be killed by seeding down heavily and mowing for a few years. Meadows badly infested with carrot, daisy or hawkweed (paint-brush or hieracium), or dandelion should be broken up, thor oughly tilled and put in rotation until it is safe to ]ay them down to grass again.
Roadsides and waste places should be kept clean.
Most states or localities have laws to compel property owners to mow the roadsides. It is probable that these weedy roadsides are less real menace to farming lands than is popularly supposed; but the laws should be enforced, nevertheless, for the effect of attractive roadsides in elevating public taste is everywhere worth consideration.
It would not be right to leave the impression that all weedy fields are necessarily poorly managed fields. In humid climates it is usually better that ground be bearing plants than that it be idle. Nature covers all the waste and raw places; and nature knows. If land is to go fallow for any rea son, it may be very good practice to let the weeds grow, with the pur pose of plowing them down for humus. The carcass of a weed may make just as good humus as that of a plant in good standing. Weeds in orchards may make good cover crops; although this does not mean that other plants may not make better ones.
The kinds of plants that are known as weeds are legion, but the really important or belligerent kinds in any community will usually not exceed two dozen. They are mostly homely plants, but this does not in the least interfere with their efficiency as weeds. A description of the kinds of weeds would scarcely be worth the while in this Cyclopedia, where every inch of space is needed for the most significant matters. The pictures will identify a few of the old friends.
Of course, everybody deplores weeds. They always have. They probably will continue to deplore them even after this Cyclopedia is printed. But it would be an interesting question if some one were
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 armbellif cral, 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 (Cicala mneulata) 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 oat of the soil by washing, freezing, or other causes in early spring." The poison hemlock (Corium maculatuni) contains "the well-known volatile alkaloid, conifie, 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); B. menata, 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 affected 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. III; and there are others that have medicinal qualities, and these are mentioned in Part III of the present volume.