Part 63. The number of plants which poison the skin by contact is fortunately much smaller than the number of those poisonous to eat. Among the latter which have been already mentioned the death-cup, the fly-amanita, and the snow-on-the-mountain are the only ones poisonous to handle. The milky juice of the snow-on-the-mountain applied to the skin often causes intense itching and inflammation accompanied by blisters. The same is true of the juice of the nearly related caper spurge (Fig. 207) and of other spurges common in gardens. The colorless juice of several species of buttercups or crowfoots, especially the tall buttercup (Fig. 208) and the ditch crowfoot (Fig. 209), blister the skin. These and related species are sometimes used by European beggars to produce sores as a means of exciting compassion.

Fig. 207. Caper Spurge (Euphorbia Lathyris, Spurge Family, Euphorbiacece). a, upper half of plant, 1/3; b, fruit, 1/1. (Chesnut.) Annual growing 1 m. or less in height; leaves in four ranks; flowers greenish yellow; fruit somewhat fleshy. Native home, Europe; growing in old gardens and as a weed in Eastern States.

Fig. 207.-Caper Spurge (Euphorbia Lathyris, Spurge Family, Euphorbiacece). a, upper half of plant, 1/3; b, fruit, 1/1. (Chesnut.)-Annual growing 1 m. or less in height; leaves in four ranks; flowers greenish yellow; fruit somewhat fleshy. Native home, Europe; growing in old gardens and as a weed in Eastern States.

Fig. 208. Tall Buttercup (Ranunculus acris. Crowfoot Family, Ranunculaceoe). Base of plant showing roots and leaves, 3/8. Flowering top, 3/8. Fruit enlarged. (Britton and Brown.) Perennial herb, growing about 1 m. or less in height; leaves hairy; flowers bright yellow; fruit dry. Native home, Europe; common as a weed in Northern States and Canada.

Fig. 208.-Tall Buttercup (Ranunculus acris. Crowfoot Family, Ranunculaceoe). Base of plant showing roots and leaves, 3/8. Flowering top, 3/8. Fruit enlarged. (Britton and Brown.)-Perennial herb, growing about 1 m. or less-in height; leaves hairy; flowers bright yellow; fruit dry. Native home, Europe; common as a weed in Northern States and Canada.

Fig. 209. Ditch Crowfoot (Ranunculus sccleratus, Crowfoot Family, Ranunculaceoe). Base of plant, 3/8. Flowering and fruiting top, 3/8. Flower, enlarged. Fruit, enlarged. (Britton and Brown.) Annual herb growing 15 60 cm. tall; leaves smooth; flowers yellow; fruit dry. Native home, Eastern North America and Eurasia.

Fig. 209.-Ditch Crowfoot (Ranunculus sccleratus, Crowfoot Family, Ranunculaceoe). Base of plant, 3/8. Flowering and fruiting top, 3/8. Flower, enlarged. Fruit, enlarged. (Britton and Brown.)-Annual herb growing 15-60 cm. tall; leaves smooth; flowers yellow; fruit dry. Native home, Eastern North America and Eurasia.

In the United States by far the worst and most frequent cases of poisoning by contact come from the poison-ivy (Fig. 210) and the poison-sumac (Fig. 211) of the East, and certain of their relatives which live in other parts of the country. Poison-ivy may be distinguished from other common vines for which it is apt to be mistaken, by the fact that its leaflets are in threes and its fruit white. Poison-sumac may be distinguished from the other common sumacs and other shrubs which it resembles, by the smoothness of its twigs and leaves and the even edge of its leaflets together with the slender cylindrical form of the part which bears them, the drooping of the flower-clusters and the greenish-white color of the hanging fruit. The symptoms of poisoning by either plant are inflammation with itching, swelling, and eruption. The poisonous principle of both species has recently been discovered to be a fixed oil, called cardol, which is soluble in alcohol. Hence the treatment recommended is to rub thoroughly the affected part every few hours with a concentrated solution of sugar of lead in alcohol of 50-75% strength. As alkalis convert the oil into a harmless soap, relief is also found by the application of a strong solution of cooking soda, as soon as possible after the poisoning.

Fig. 210. Poison ivy (Rhus Toxicodendron, Sumac Family, Anacardiaceoe). a, spray showing air roots and leaves, 1/4; b, fruit, 1/4. (Chesnut.) Climbing or trailing shrub becoming 6 15 m. long, sometimes erect and bushy; leaves smooth or downy; flowers green; fruit smooth, waxy, grayish. Native home, North America.

Fig. 210.-Poison-ivy (Rhus Toxicodendron, Sumac Family, Anacardiaceoe). a, spray showing air-roots and leaves, 1/4; b, fruit, 1/4. (Chesnut.)- Climbing or trailing shrub becoming 6-15 m. long, sometimes erect and bushy; leaves smooth or downy; flowers green; fruit smooth, waxy, grayish. Native home, North America.

Fig. 211. Poison sumac (Rhus Vernix, Sumac Family, Anacardiacece). Fruiting branch. (Chesnut.) Shrub or tree 2 15 m. tall; leaves smooth, shining green above, pale beneath; flowers green; fruit grayish. Native home, Eastern North America, in moist ground.

Fig. 211.-Poison-sumac (Rhus Vernix, Sumac Family, Anacardiacece). Fruiting branch. (Chesnut.)-Shrub or tree 2-15 m. tall; leaves smooth, shining green above, pale beneath; flowers green; fruit grayish. Native home, Eastern North America, in moist ground.

A fixed oil similar to cardol has been found to be the cause of poisoning by two of our native orchids known as lady-slippers (Figs. 212, 213). The symptoms are like those just described, and the treatment recommended is the same.

Fig. 212. Showy Ladies' Slipper (Cypripedium hirsutum, Orchid Family, Orchidaceoe). Leaf. Flower. Fruit, 1/3. (Britton and Brown.) Perennial herb 30 60 cm. tall; leaves hairy; flowers white and crimson; fruit dry. Native home, Eastern North America. Poisonous to touch.

Fig. 212.-Showy Ladies' Slipper (Cypripedium hirsutum, Orchid Family, Orchidaceoe). Leaf. Flower. Fruit, 1/3. (Britton and Brown.)- Perennial herb 30-60 cm. tall; leaves hairy; flowers white and crimson; fruit dry. Native home, Eastern North America. Poisonous to touch.

Fig. 213. Yellow Ladies' Slipper (Cypripedium parviflorum, Orchid Family, Orchidaceoe). Base of plant. Flowering top, 1/3. Stigma and stamens, enlarged. (Britton and Brown.) Similar to the showy ladies' slipper but flowers greenish yellow, more or less suffused or streaked with madder purple. Native home, North America.

Fig. 213.-Yellow Ladies' Slipper (Cypripedium parviflorum, Orchid Family, Orchidaceoe). Base of plant. Flowering top, 1/3. Stigma and stamens, enlarged. (Britton and Brown.)-Similar to the showy ladies' slipper but flowers greenish yellow, more or less suffused or streaked with madder-purple. Native home, North America.

Fortunately there are many persons who are not affected by handling poison-ivy, poison-sumac, or either of the orchids mentioned; and there are other persons upon whom the effect is but slight. On the other hand, certain persons, particularly women and children, have skins so sensitive as to be poisoned by handling plants which are commonly regarded as harmless. Thus one occasionally hears of a person who cannot handle the herbage of the carrot or parsnip, or who cannot wash parsnip roots without being poisoned. In all such cases, as also in cases of poisoning by the other plants referred to in this section, the treatment recommended is much the same as that given for ivy poisoning.