MacDougal: POISONOUS INFLUENCE OF CYPRIPEDIUM. 33 



The poisoning may he due to mechanical injury, as the pierc- 

 ing of the skin by stiff hairs of special poison organs, such as 

 the glandular hairs of the nettles, or to a volatile substance, 

 such as the toxicodendric acid of the poison ivy. The follow- 

 ing list includes some native plants of Minnesota, which have 

 been definitely ascertained to be more or less poisonous, in the 

 manner indicated. ^ 



Bhus vernix Linn. Poison ivy. 



Bhus radicans LiNTsr. Poison oak. 



Spathyema foetida (Linn.) Raf. Skunk cabbage. 



Bidens frondosa Linn. Beggar's ticks. 



Erigeron canadense Linn. Fleabane. 



Xanthium canadense Mill. Cockleburr. 



Polygonum hydropiper Linn. Smartweed. 



Polygonum acre HBK. Water pepper. 



Aciaea spicata alha (Linn.) Mill. Baneberry. 



Anemone quinquefolia Linn. Wind flower. 



Anemone hirsutissima (Pursh) MacM. Pasque flower. 



Euphorbia corollata Linn. Spurge. 



Euphorbia marginata Pursh. "Snow on tlie mountain." 



Banunculus septentnonalis PoiR. Crowfoot. 



Banunculus sceleratus LiNN. Cursed crowfoot. 



Urtica gracilis Ait. Nettle. 



Laportea canadensis (LiNN.) Gatjdich. Wood nettle. 



The above list includes only the plants of the state which are 

 known to be poisonous to the touch, and is not inclusive of a 

 large number which are more or less suspected of being so. 

 The present article contemplates the addition of two species of 

 Cypripedium to the list. 



On many different occasions, and from widely separated 

 localities, unconfirmed reports have been made of the poison- 

 ous effects of Cypripediitm spectahile and C. pubescens. 



In the Bulletin of the Torr-eij Botanical Club for February, 

 1875, is found the following note.^ 



"Prof. H. H. Babcock, in a communication to The Pharmacist, Chicago, 

 January, 1875, states that, being especially susceptible to poisoning by 

 Ehus Ibxicodendron, he for several years took every precaution against it. 

 He not only was careful to avoid contact with the plants, but would not 

 collect specimens of other plants growing near the Bhus, and went so far 

 as to avoid handling fresh specimens gathered by others for fear these 

 had been in contact with it. Notwithstanding all this, he found that 

 late in May or early in June of each of several successive years he was so 

 severely poisoned as to be conflned to his room for several days, his face 

 presenting the appearance usual In poisoning by Bhus. Upon referring to 



2 White : Dennatitis Venenata. Boston. 1887. 



Cornevin : Des Pktnles Vetitneuses. Paris. 1887. 

 3. vol. 6, p. 15. J875. 



