Poison ivy

“ Poison-ivy can be grubbed out by hand quite readily early in spring and late in fall. When the ground is soft after rains the roots come out in long pieces. Grubbing when the soil is dry and hard is almost futile, since the roots break off in the ground, leaving large pieces that later sprout vigorously. Eradication by grubbing is permanent if well done. Because of his close contact with the plants, the person doing the grubbing should have a high degree of immunity to ivy-poisoning. ”

“ Most chemicals used on poison-ivy are injurious to the foliage of all kinds of plants and must be applied with caution if the surrounding vegetation is valuable. During the early part of the growing season the leaves of the poisonous plants usually tend to stand conspicuously apart from those of adjacent plants and can be treated separately if sprayed with care. Later the leaves become intermingled and injury to adjacent species is unavoidable. Chemicals other than oil are not injurious to the thick bark of an old tree, and poison-ivy clinging to the trunk can be safely sprayed with them. ”

“ By studying a large number of the leaves it is usually possible to detect on every Boston ivy plant some leaves that have only one deeply lobed blade or leaflet, while the poison-ivy always has the three leaflets. A number of other plants are easily confused with poison-ivy. No specific rule can be observed that will easily rule out all possibility of confusion. ”

“ The poison of the ivy, though always present, probably, like all sap, varies slightly in activity with the season, though perhaps not more than does man's power of resisting it, for the warm, perspiring skin of summer with its open pores takes in and throws out juices much more readily and is more easily irritated than the dry, firm skin and contracted pores of the exposed parts in winter. Aside from the sand form, all parts of the poison ivy are poisonous at all seasons, the root being by far the most virulent of all. ”

“ Poison-ivy vines climbing on trees should be severed at the base and as much of the vine as possible pulled away from the tree. Often the roots of the tree and weed are so intertwined that grubbing is impossible without injury to the tree. Close mowing of the poison-ivy shoots at frequent intervals is the only remedy. Roots and stems removed in grubbing should be burned or otherwise destroyed, since the dry material is almost as poisonous as the fresh. Care must be taken to keep out of the smoke. ”

“ For example, poison ivy (Rhus toxicodendron or Rhus radicans) probably the best known poisonous plant in America, being found in all the States except those in the extreme West, is often confounded with and popularly called "poison oak." The true poison oak is the Rhus diversiloba of the Western States. [1] The third and most poisonous species of this plant is Rhus venenata or Rhus vernix; it is the Rhus vernicifera of Japan, from which Japanese lac is obtained. It is popularly known in the United States as "poison sumach," "poison dogwood" and "poison elder." ”

“ Through experience, many people know that they are susceptible to poisoning by poison-ivy, poison-oak, or poison sumac, while some others either have escaped contamination or have a certain degree of immunity. The extent of immunity appears only relative, and absolute immunity to the toxic principle apparently does not exist. Persons who have shown a degree of immunity upon repeated contact with the plants may develop poisoning on subsequent exposure. ”

“ From a clinical study of Rhus poisoning, Pfaff came to the conclusion that the poison must be a non-volatile skin irritant. The more volatile the irritant, the quicker is its action on the skin. Formic acid acts very quickly; acetic acid, less volatile than formic, acts more slowly, but still much more quickly than poison ivy, the latent period of which is usually from two to five days. Pfaff thought that the volatile acid obtained by Maisch might have contained some of the poisonous principle as an impurity, but that it would not produce the dermatitis if prepared in a pure state. ”

“ ERADICATION OF PLANTS
Poison-ivy [2] can be killed either by mechanical means, such as digging, or by applying chemical herbicides. The best modern herbicides are so deadly to plants that a single treatment kills all the leaves and 90 percent or more of the roots. This is the easiest and least dangerous way to destroy these poisonous pests. There are places, however, where chemicals cannot be used, as in hedges and shrubbery where the poison-ivy is closely mixed with the valuable plants. In such situations, hand-pulling is the only satisfactory method. ”

“ Thus poison ivy has no apparent external effect upon animals, and a few of them eat its leaves with impunity; and it acts upon the skin of the majority of persons with varying intensity—on some hardly at all, while others are extremely sensitive to it. ”

“ A solution consisting of one-seventh ounce in 1 gallon of water sprayed on poison-ivy foliage kills all leaves hit and may kill the roots. In the concentration used in weed killing 2,4-D is not believed to be harmful to animal life, but until this point can be thoroughly clarified the chemical should be used with reasonable caution to avoid poisoning. 2,4-D is not flammable and is not corrosive to spray machinery. ”

“ Old plants of poison-ivy produce an abundance of seeds, and these are freely disseminated, especially by birds. A poison-ivy seedling 2 months old usually has a root that one mowing will not kill. Seedling plants at the end of the first year have well-established underground runners that only grubbing or chemicals will kill. Seedlings are a constant threat as long as old poison-ivy is in the neighborhood. ”

“ Self-treatment also has other dangers, as the symptoms of ivy poisoning may be confused with those of other conditions and harm may be done by improper treatment. In all cases the safest procedure is to consult a physician.
Some tried remedies are effective on certain individuals and ineffective on others. Sometimes a person will find one remedy effective and later, to his surprise, get very little relief from it. A large number of patent medicine remedies of doubtful value are commonly offered for sale. ”

“ Plowing is of little value in combating poison-ivy unless followed by persistent stirring with a cultivator or harrow, to keep all roots loosened from the soil. Otherwise plowing merely propagates the weed.
Mowing with a scythe or sickle is a common method of attacking poison-ivy, but it has little effect on the roots unless frequently repeated. The number of cuttings required to kill depends upon the age of the plants and the size of the roots, but is seldom less than four. New shoots should be cut as soon as the first leaf on each stem is full size. ”

“ The skin irritant of poison-ivy, poison-oak, and poison sumac is the same toxic agent. It is a nonvolatile phenolic substance called urushiol and is found in all parts of the plant, including roots and fruit. It occurs in great abundance in the plant sap. The danger of poisoning is greatest in spring and summer, when the sap is abundant, and least late in fall or in winter. ”

“ The most effective method of prevention is to eradicate the plants, and wherever possible this should be done. They should not be allowed to grow in lawns or gardens, with ornamental shrubbery, or on houses. Communities should not countenance the growth of poison-ivy or poison-oak in school grounds, on public roadways, or in parks, especially those frequented by children. The cost of medical aid for one season in treating pupils using an ivy-infested schoolyard is likely to be more than that of eradicating the plants, to say nothing of the suffering and inconvenience they may cause. ”

“ You have been hearing about good fairies and good old Mother Carey and Medicine in the Sky. Now I am going to warn you against the three-fingered Demon, the wicked snakevine that basks on stone walls and climbs up the tree trunk, and does more harm than all the other plants, vines, trees, and bushes put together; for it is not like the Deathcup, easy to see and easy to let alone.
This is the Poison Ivy. Does it not look poisonous as it crawls snake-like up some trunk, sending suckers out into the tree to suck the sap; and oozing all over its limbs with poison in tiny wicked little drops? ”

“ It is important to become poison-oak or poison-ivy conscious. This can be accomplished only by learning to know the plants by repeated experience in observing them in their various forms. Persons who learn both to know and to avoid the plants can save themselves much inconvenience and discomfort. The simple means of learning to recognize them will pay big dividends. It is the first step to the prevention of poisoning and to the eradication of the pests from private grounds and public places. ”

“ Very few persons have a sufficient degree of immunity to protect them from poisonous plants, and many do not recognize them in the various forms that they assume in different parts of the country.
One or more kinds of poison-ivy—common poison-ivy, oakleaf poison-ivy, and western poison-oak—occur in abundance in almost every part of the United States. Poison sumac is of more limited distribution and occurs chiefly east of the Mississippi River, usually in swampy regions. ”

“ In normal times sodium arsenite is obtainable in both powder and liquid form. In weak solution (4 to 6 ounces per gallon of water) the chemical can be used as a spray to destroy poison-ivy. Like sodium chlorate spray, it kills the leaves but not the roots, and five or six treatments may be required. The solution kills the leaves of all plants impartially and will also kill the young tender bark of shrubs and trees. ”

“ Poison Ivy, Lead Water and Laudanum Relieves.—"Application of cold lead water, made in proportions of two drams of sugar of lead, half an ounce of landanum to half a pint of water and applied by means of cloths. The patient should eat a cooling, light diet and use a good saline cathartic, such as rochelle salts, etc."
Poison Ivy, Excellent Cure for.—"Copperas mixed with sour milk; put in all the copperas the milk will dissolve. I knew of a very bad case to be cured by this after a few applications. Care should be taken not to let it get on the clothing, as it burns badly." ”

“ Many people are not so immune as they believe, and it is common sense to wear leather gloves with gauntlets and a shirt with long sleeves. If care is taken to prevent the poison-ivy from touching the face, and if the clothes, including the gloves, are burned or thoroughly washed after use, severe poisoning may be avoided. ”

“ Most of the vines or shrubs of poison-ivy produce some flowers that are always in clusters arising on the side of the stem immediately above a leaf. The flowers are rather inconspicuous among the leaves, as may be noted in figure 7, but they are in quite distinct clusters, as shown in figure 8, A. Frequently the flowers do not develop or are abortive and no fruit is produced. When fruits do develop they serve as a positive way of identifying the plant. The berries are not easily confused with the fruits of other plants. ”

“ The poison-sumac, swamp-sumac, or dogwood (Fig. 3) is ten times more severe in its poisoning qualities than the poison-ivy. It grows from six to ten feet in height, in low marshy grounds. The berries are smooth, white, or dun-colored, and in form and size closely resemble those of the ivy. ”

“ Frequent observation and recognition of the plants as they are encountered almost daily is the best way to become poison-oak or poison-ivy conscious. Nonpoisonous sumacs are easily distinguished from the poisonous species by the seed heads and leaves. ”

“ Figure 18.—Western poison-oak: A, Top of shrub, with leaves and fruit; B, clusters of fruit after leaves have fallen.
Low-growing plants, especially those exposed to full sunlight, are often quite woody and show no tendency for vining. Low-growing plants with woody stems are common in pasture areas or along roadsides. Livestock in grazing do not invade the poison-ivy shrub, and as a rule these plants continue to spread both by root-stock and seed.
Figure 19.—A large poison sumac shrub about 15 feet tall, growing on the edge of a swamp. ”

“ These wild leaves have only three fingers and you must never touch them. You see these berries are waxy white and the berries on Mr. Giant's woodbine were purple. Remember, Buster, unless the leaves have five fingers like your paws, they are poison ivy. Now trot along with Hopsy and Webbie over to Wild Rose Cottage. Tell Grand-daddy all about it and ask him to fix you up."
Dr. Whiskers washed the three scared little patients in salt water.
"I am afraid you will be some puffed-up youngsters in the morning," he said. "But I guess you will know poison ivy next time." ”

“ There are great differences in individual susceptibility to some [p.14] of these plant poisons. One familiar plant, the so-called poison-ivy, is not harmful for many people even when handled recklessly; it can be eaten with impunity by most domestic animals. ”

“ The motor camper, however, will not be likely to suffer exposure to these poisons.
It is the children that most frequently get poisoned, and on a camping tour they are most likely to get poisoned by things found in the woods or near the camp. The most common source of poisoning is the poison ivy. This is sometimes very painful, but seldom dangerous to life. Pokeberries are said by some authorities to be poisonous, but in some sections of the country poor people gather them and use them as filling for pies, the same as elderberries, without any apparent ill results. ”