Poison oak

“ It may be noted even in this case that the tendency is for individual branches to continue an upright growth rather than become entirely dependent upon other objects for support. In some areas, especially in woodland, poison-oak may grow principally as a vine. Areas have been noted where 70 to 80 percent of the trees leaves and flowers. in a wooded area support vines running more than 25 or 30 feet in height, although the most common form of the plant is the shrub. ”

“ The sides of the canon are densely covered with the vine- like shrub known as the "poison-oak" which affects some people so terribly, even the wind blowing over it poisoning them so as to produce frightful swellings and eruptions of the face and glands, blindness, deafness, and sometimes even death itself. This plant has no effect whatever on any animal, nor on many men. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ 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. ”

“ This is a small shrub generally not more than a foot in height, though sometimes as tall as a man's head, with dark venomous looking leaves resembling in shape those of the oak. Its poison is of the most subtile and diffusive nature, approaching more nearly, perhaps, to that of the fabled upas than any other in the vegetable kingdom. Some, indeed, can handle it with impunity, while with others not only the merest touch but even holding it a few inches from the hands or face is followed by most painful consequences. ”

“ 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. ”

“ The poison may remain on the fur of animals for a considerable period after they have walked or run through poison-ivy plants. Smoke from burning plants will carry the toxin and has been reported to cause severe cases of poisoning. Cases of poisoning of children from eating the fruit have been reported. A local belief that eating a few leaves of these plants will develop immunity in the individual is unfounded. It never should be attempted. No part of the plant should ever be taken internally, as it is a violent irritant and poisonous to man. ”

“ 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. ”

“ Occasional isolated plants are found outside of swampy regions. Apparently these plants are started from seed distributed by birds. The plants in dry soil usually do not become more than a few feet tall. They are likely to cause poisoning to unsuspecting individuals, as single isolated plants are not readily recognized, especially out of their usual region.
The leaves of the poison sumac are divided into 7 to 13 leaflets, arranged in pairs with a single leaflet at the end of the midrib (fig. 21) . ”

“ Fuel oils are widely used for destroying vegetation, particularly by highway departments in States having oil resources. When sprayed on poison-ivy, fuel oil brings about a slow but fairly sure death of the plants. ”

“ Poisoning by these plants is largely preventable. A knowledge sufficient to identify them in their various forms is easily gained by anyone who will make a study of pictures and general descriptions and train himself by a little diligent practice to observe the plants in his locality. ”

“ Stuart held out his hand, feebly.
"I didn't know there were any trees which hurt you unless you touched them," he said.
"Plenty of them," answered the scientist. "There are over a hundred plants which give off smells or vapors which are injurious either to man or animals. Some are used by savages for arrow poisons, others for fish poisons, and some we use for medicinal drugs. Dixon records a 'gas-tree' in Africa, the essential oil of which contains chlorine and the smell of which is like the poison-gas used in the World War. ”

“ I have understood that the soil in which the trees affording the poison grow, for a great space round about produces no grass nor any other vegetable growth, and that the poison is properly a water or liquid, flowing from a bruise or cut made in the bark of those trees, oozing out as sap does from plants that afford milky juices.... When the liquid is being drawn from the wounded tree, no one should carelessly approach it so as to let the liquid touch his hands, for by such contact all the joints become stiffened and contracted. ”

“ As to its poisonous qualities, all authors agree that every species of the family is very poisonous, the A. ferox of the Himalaya being probably the most so. Every part of the plant, from the root to the pollen dust, seems to be equally powerful, and it has the special bad quality of being, to inexperienced eyes, so like some harmless plant, that the poison has been often taken by mistake with deadly results. This charge against the plant is of long standing, dating certainly from the time of Virgil—miseros fallunt aconita legentes—and, no doubt, from much before his time. ”

“ So many other plants are violently poisonous, and yet yield the most valuable drugs, that the greatest care has to be used in their collection and preparation. The habit of many children of eating wayside berries should be discouraged, as some of our most innocent-looking roadside plants are actually deadly if their fruits or foliage are eaten. Fortunately only a very few plants are poisonous to the touch, notably poison ivy and poison sumac, and some of their relatives. ”

“ These organic, poisonous matters ooze through the soil into wells and springs, and as before said, may not show any bad effect for sometime, but sooner or later disease and death will surely visit the unsuspecting household and the physician’s aid be sought in vain, for with every draught of water which passes the fevered lips, the sufferer imbibes new poison and hastens the inevitable end. ”

“ Nerium oleander.—This is a well-known plant, often seen in cultivation, and seemingly a favorite with many. It belongs to a poisonous family and is a dangerous poison. A decoction of its leaves forms a wash, employed in the south of Europe to destroy vermin; and its powdered wood and bark constitute the basis of an efficacious rat-poison. Children have died from eating the flowers. A party of soldiers in Spain, having meat to roast in camp, procured spits and skewers of the tree, which there attains a large size. ”

“ The genus Aconitum appears to be that in which the poisonous properties are most prominently developed, the roots of Aconitum ferox, Wall, or Bish or Bikh of the Nepalese, ranking among the most virulent of vegetable poisons, while those of A. Napellus (the common monkshood of English gardens) are so active, as to have caused numerous accidents to Man, and are employed by the Swiss, mixed with food, to poison the Wolves which so generally infest their country. ”

“ Nine active or virulent poisons are mentioned by most ancient writers on Indian medicine, many of which are at present not identified. Most of them are apparently varieties of aconite. Besides these, they employed opium, gunja, datura, roots of Nerium odorum and Gloriosa superba, the milky juices of Calotropis gigantea and Euphorbia neriifolia, white arsenic, orpiment, and the poison extracted from the fangs of serpents. ”

“ Where the skin is poisoned, use a wash of smartweed steeped in water, or mix soot and cream, and apply it frequently; bruised Jamestown weed and cream is also good. If you have been exposed to poisonous plants, wash your face and hands immediately in salt and vinegar, or salt and water. When "corrosive sublimate," has been swallowed, the whites of two eggs taken immediately will neutralize the poison, and change the effect to that of a dose of calomel.
Persons struck by lightning should be laid on the ground, and pour water over them till life is restored. ”

“ For doing damage on the sea or among the mountains, powders are well considered—made of toads' flesh, roasted, dried, and pulverised, and subsequently cast into the air or scattered on the ground, according to the circumstances of the case. Another and very baleful poison may be made of "green water"; so potent is it that even to touch it causes instant death. ”

“ Dioscorides throws a further light on the poisons of antiquity in his great work on Materia Medica, which for fifteen centuries or more remained the chief authority on that subject. He mentions cantharides, copper, mercury, lead, and arsenic. Among the animal poisons are included toads, salamanders, poisonous snakes, a peculiar kind of honey, and the blood of the ox, probably after it had turned putrid. The sea-hare is frequently alluded to by the ancient Greeks, and was evidently regarded by them as capable of producing a very powerful poison. ”

“ Unfertilised eggs of insects have been started into growth by treatment with acids and those of frogs with mercury salts, and the germination of beans quickened by various poisonous alkaloids. In other words, graduated doses of [131] poison may alter the physiological activity of living cells, inducing pathological phenomena, while larger doses kill them.
Now we know at least one parasitic fungus which poisons the cells of its host, and kills them, with similar symptoms to those resulting from excessive doses of the above-named toxic agents. ”

“ In some regions the arrows are poisoned by the simple expedient of sticking them into the trunk of the poison-bearing tree and leaving them in this novel pincushion until required.
It is a curious fact that game killed by poisoned arrows is perfectly wholesome if the wound is carefully washed at once. The young plants also of the antiaris toxicaria supply an absorbent poison. Their sap is not as powerful as that of the full-grown trees, but on the other hand has neither its bitterness nor repulsive smell. ”

“ In the East, poisons have been used from remote times, not only for the destruction of human life, but also for destroying animals—arsenic, aconite, and opium being employed by the Asiatics for these purposes. ”

“ Others have not this power, and here the poison tree springs up. The want of self-control is the germ of the poison tree, and also the cause of its [192] growth. This tree is very vigorous; once nourished it cannot be destroyed. Its appearance is very pleasant to the eye; from a distance its variegated leaves and opening buds charm the sight. But its fruit is poisonous; who eats it dies.
In different soils the poison tree bears different fruits. In some natures it bears sickness, in some sorrow, and other fruits. To keep the passions in subjection will is needed, and also power. ”

“ The French attribute the same qualities to this plant, which the poison-tree, or Rhus vernix, has in the English colonies; that its poison is noxious to some [27] persons, and harmless to others. The milky juice, when spread upon the hands and body, has no bad effect on some persons; whereas others cannot come near it without being blistered. I saw a soldier whose hands were blistered all over, merely by plucking the plant, in order to shew it me; and it is said its exhalations affect some people, when they come within reach of them. ”