130 MANUAL OF POISONOUS PLANTS 



Nerium Oleander L. Common Oleander. 



Cultivated. The leaves are deadly poisonous to stock. Contains conessine, 

 and neriin, which has the properties of digitalin. Nerianthin bears a resemblance 

 to digitalin. 



Dr. Wilson of the Arizona Experiment Station has recently demonstrated 

 the very poisonous nature of this plant in Arizona. 



Asclepiadaceae. Milkweed Family. 



Asclepias tuberosa L. Pluerisy-Root. 



Widely distributed in Iowa, especially on gravelly knolls and prairies. 

 The leaves are more or less poisonous to stock. However, honey bees collect 

 considerable honey from this plant. 



Asclepias incarnata L. Swamp Milkweed. 



Poisonous probably like the preceding. The root is emetic and cathartic. 



Asclepias syriaca L. Milkweed. 



Poisonous. Contains the glucoside asclepione, an amorphous bitter sub- 

 stance. 



Asclepias speciosa Torr. Showy Milkweed. 



Poisonous. This species is found in Western and Northwestern Iowa to 

 Utah. 



Asclepias campestris, Decne. Milkweed. 



Commonly cultivated in gardens southward. It is said to be poisonous. 



Asclepias eriocarpa Benth. Milkweed. 



Common in California and adjacent regions. According to Chesnut sheep- 

 men in California very much fear this weed. It has broad mullein-like leaves. 



Asclepias mexicana Cav. Narrow Leaved Milkweed. 



Native to California, Oregon and Nevada. According to Chesnut sheep 

 and calves are not infrequently poisoned by eating this plant and cows have 

 been poisoned by eating hay contaminated with it. 



Convolvulaceae. Convolulus Family. 



Ipomoea pandurata Meyer. Wild Potato Vine. Man of the Earth. 



The large root is poisonous. Contains the gulcoside impomoein. 



Convolvulus sepium L. Hedge Bindweed. 



The plant produces a somewhat disagreeable odor. Dr. Schaffner states 

 that it is supposedly poisonous to swine. Jalap contains several glucosides which 

 also probably occur in our Morning Glory. One is convolvulin. 



Cuscuta epithymum Murr. Clover and Alfalfa Dodder. 



Dr. J. Q. Taylor of Lisbon, Ohio, in writing to Prof. A. D. Selby stated 

 that dodder produced a bowel trouble in horses, and Dr. Jenkins of New Haven 

 writes that clover hay containing a great deal of dodder produced scours. He 

 added that the hay had moulded badly, although the injury could not be definitely 

 traced to dodder. Some exotic dodders are poisonous. The dodder must, 

 therefore, be looked upon with suspicion. 



Polemoniaceae, Polemonium Family. 



Gilia aggregata Spreng. Cypress plant. 



Common in the Ry. Mts. to Neb. This species according to Greshoff con- 

 tains a considerable amount of saponin and is very poisonous. He lists several 

 other species which contain this substance. 



