IOWA ACADEMY OF SCIENCE 155 
URTICALES. 
Urticaceae. 
72. Maclura aurantiaca, Nutt. Osage orange. 
Cultivated especially in the southern part of the state. The leaves and 
fruit are more or less poisonous. The thorns upon the plant produce serious 
injuries giving rise to inflammation. 
73. Humulus lupulus, L. Common Hop. 
Hop pickers often have an inflammation of the hands. It is a sedative. 
Hop contains choline C5H15NO2, lupulic acid C32H50O7, oil of humulus C 10 H 10 and 
CioHieO. 
74. Cannabis sativa, L. Hemp. 
Naturalized in many parts of the state. The narcotic effect of the resin of 
the plant is well known and in India an intoxicating drink is made from the 
juice of the leaves. Probably it contains the substance cannabin , oxycannabine 
C20H20N2O7 and cannabine Ci 8 H 2 o. 
75. Urtica dioiea, L. Stinging nettle. 
The urticating properties of our common nettle are known to all who have 
had any experience in collecting the plants; there is at first a reddening, fol- 
lowed by a swelling, intense burning, and a small amount of itching. It 
contains formic acid H2CO2. 
76. Urtica gracilis, L. Slender nettle. 
Injurious, like the preceding. More widely distributed than the preceding. 
77. Laportea canadensis, Gaud. Wood nettle. 
This plant is even more widely distributed than the preceding nettles. It 
is found in deep woods. Produces an irritation of the skin like common nettle. 
POLY GONALE S. 
POLYGONACEAE. 
78. Rumex acetosella, L. Sheep sorrel. 
The plant is widely distributed over the state and is becoming more com- 
mon. Said to be poisonous to horses and sheep. Contains oxalic acid. 
79. Fagopyrum esculentum, Moench. Buckwheat. 
A dermatitis produced by the eating of buckwheat cakes is well known to 
most people and occasionally where screenings of this material are fed in 
quantities to hogs a similar rash is produced. Buckwheat straw is also con- 
sidered poisonous. The plant contains the glucoside indican . 
80. Fagopyrum 'tartaricum, Gaertn. 
Poisonous like the preceding. 
81. Polygonum acre, H B K. Smartweed. 
The acrid properties of many of the species of Polygonaceae are well known. 
This species is widely distributed in the state. Contains probably polygonic 
acid. 
82. Polygonum hydropiper, L. Smartweed. 
Poisonous like the preceding. 
CENTROSPERMEAE. 
Chenopodiaceae. 
83. Chenopodium anthelminticum, L. Worm-seed. 
