Poison Ivy and Poison Dogwood 
TWO NOXIOUS WILD PLANTS AGAINST WHICH YOU SHOULD TAKE PRECAUTIONS-HOW 
THEY MAY BE EASILY RECOGNIZED AND WHAT REMEDIES ARE USEFUL AFTER EXPOSURE 
by Annie Oakes Huntington 
the days shorten in early autumn, and 
the night air grows crisp and cool with 
the approach of frost, nature’s miracle 
of the changing leaves transforms 
mountain forests, wooded hillsides, 
and low, swampy thickets into a bril¬ 
liant pageant of color nowhere more 
varied or striking than in our North¬ 
eastern States. 
Among the many different trees and 
shrubs, each contributing their pecu¬ 
liar color tones to the scheme, none is 
more pronounced, in having a certain 
shining, scintillant quality which im¬ 
mediately arrests the attention, than 
the poison ivy and poison dogwood — 
both members of the genus Rhus. 
Their beautiful, glossy leaves flash 
scarlet in the sunshine, and entice the 
unwary, while beneath their beguiling- 
exterior lies a poison more virulent in 
its effect on those coming in contact 
with it than that of any other Amer¬ 
ican plant. 
The poison dogwood, or poison su¬ 
mac ( Rhus vernix ) is more limited 
in its range than that of the poison ivy 
(Rhus radicans). It is found from 
northern New England to northern 
Georgia and Alabama, and westward 
to northern Minnesota, Arkansas and 
western Louisiana, whereas the poison ivy is found in almost 
every State in the Union, with the exception of those in the ex¬ 
treme West, where it is replaced by the poison oak. In its habitat 
the poison dogwood is confined to moist, swampy places, low, wet 
thickets, and the borders of ponds; but the poison ivy runs riot 
everywhere, up the shaded trunks of trees in the woods, along 
walls in open pastures, over banks by dusty roadsides, and even 
pricks its way through the burning white sands of the dunes along 
the seacoast. 
The poison dogwood is a shrub which sometimes becomes 
twenty feet high, with a broad head and clustered stems; the 
poison ivy is a climbing, or trailing, woody vine. In foliage a 
marked difference is seen between these sister plants. The 
leaves of the poison dogwood are unequally pinnate, with from 
seven to thirteen obovate-oblong leaflets, a shining green on the 
upper surfaces, and paler beneath; those of the poison ivy are 
trifoliate, the three leaflets varying in shape from ovate to those 
which show a tendency to become four-sided. The flowers of 
both species are much alike, yellowish-green and small, in loose, 
slender panicles, those of the poison dogwood measuring three to 
ten inches long, while the panicles of the poison ivy are seldom 
more than four inches in length. The fruit of both is a waxy 
white, or gray drupe, but the berries are thick-set along the stems 
of the poison ivy, and hang in long, graceful racemes from those 
of the poison dogwood. 
The toxic principle in both is a non-volatile oil, called toxi- 
codendrol, and found in every part of both plants, in stems, 
branches, leaves, bark, roots, fruit, and even in the fine pollen 
dust from the flowers, in sufficient quantity to produce a bad case 
of poisoning if the wind happens to blow it across the hands 
or face. 
Cases of poisoning are most frequent in summer, when the blood 
is overheated, and the pores of the skin are open and susceptible 
to the action of the poisonous juice when it comes in contact with 
the skin. It usually develops within four days of the exposure, 
and lasts about two weeks in severe cases. It may be recognized 
by small blisters which appear on the skin, filled with a watery 
fluid and accompanied with itching and burning sensations. In 
extreme cases these vesicles spread and become confluent, and the 
swelling and irritation cause great discomfort. The only effective 
treatment in a case of this poisonous eruption is a wash which 
mechanically removes the poisonous oil from the skin. The toxic 
principle is soluble in alcohol, and a weak solution (fifty to 
seventy-five per cent.) may be used, adding to it all the powdered 
sugar of lead (lead acetate) the alcohol will dissolve. Bathe 
every half hour with constant changes of fresh solution. This 
treatment, however, is not one whit more effectual than successive 
and thorough washings with common yellow soap, water and a 
scrubbing brush, a method strongly upheld by the most scientific 
investigators of the subject. An article on the active principle of 
Rhus toxicodendron and Rhus venenata by Franz Pfaff, in the 
Journal of Experimental Medicine (March, 1897), will be of in¬ 
terest to those who wish to read the account of his experiments. 
Poison ivy grows in widely differing surroundings; it seems as much at 
home on the sand dunes as in the deep woods 
( 87 ) 
