Native. Perennial. Propagates by seeds and by rootstocks. Time of bloom: Late May to July. Seed-time: Fruits attain full size in August but remain on the stem until late in winter. Range: Nova Scotia to British Columbia, southward to Florida,
Arkansas, and Utah. Habitat: Roadsides and waste places, fence rows, and borders of woods.
Fig. 191. - Poison Sumac (Rhus Ver-nix). X 1/4.
A very poisonous plant, far too common everywhere, for to many persons the touch of it brings disaster, blotching the skin with burning " water-blisters " and causing the flesh beneath to swell hideously and throb with a pain so intense as to be alarming. Fortunately such an attack leaves no scars and the general health is not injured. Chemical analysis has shown that the poison is a nonvolatile oil, found in all parts of the plant, even the seasoned wood, but especially in the growing leaves. It is insoluble in water, therefore washing the skin after contact merely serves to spread the trouble; but alcohol will at once dissolve and remove it, and, if applied soon enough, will prove the prevention that is better than cure. If too late for that, a little powdered sugar of lead, dissolved in alcohol, will check the eruption and soothe the pain. This remedy is also a poison, and care must be taken to keep it out of eyes and mouth, and of course it should not be used if the vesicles have broken; in such case dilute extract of Grindelia will check their spread and soothe the smart.
The plant is sometimes an erect and bushy shrub, sometimes prostrate and trailing, sometimes a long, woody vine, climbing tall trees by means of aerial rootlets. Leaves compound, with three leaflets, ovate to rhombic, pointed, usually entire but sometimes scalloped or irregularly few-toothed, the two lateral ones sessiie or on very short stalks, the terminal one longer. In form they are somewhat like the leaflets of the Virginia Creeper, or Woodbine (Psedera quinquefolia), but it should be remembered that those are five in number like the fingers of the hand, and can be safely handled; but "Leaflets three, let it be." Flowers in loose, axillary panicles, small, greenish white, with five-parted calyx, five petals, five stamens and one-celled ovary. Fruit also greenish white, smooth, and waxy, dangling in clusters of about the size of small currants,
Fig. 192. - Poison Ivy (Rhus Toxicodendron). X 1/4 each containing one hard seed. Crows and other birds eat the fruits, apparently without harm, and void them along fences and telephone routes. The pest is increasing throughout the country, for most people are so afraid of it that it is left unmolested to multiply its kind. (Fig. 192.)
Some fortunate persons are quite immune to the bad effects of the plant, and one of these might be hired to grub it out and burn it, taking care that no one inhales the intensely irritant smoke or gets it in the eyes. Or a few drops of sulfuric acid (handle with care), applied every few days to the woody stem near the roots, will kill the plant; or hot brine or caustic soda will destroy it.