66 



MANUAL OF POISONOUS PLANTS 



Fig. 16g. The flowers of Black Locust (,Robinia 

 pseud-acacia) produces a toxic nectar. (Ada Hayden). 



Fig. I6I1. The wilted and old 

 flowers of Wild Cherry (Prunus) 

 produce a cyanogentic poisonous 

 odor. (Ada Hayden). 



We have a long list of plants that act injuriously 

 Mechanical Injuries in a mechanical way. Among the best known of these 

 are Wild Barley or Squirrel-tail Grass {Hordeum juha- 

 tuni) and the related species, which, by mechanical means, injure sheep, horses, 

 and cattle. The awned heads, when eaten with hay or. grass, break up into 

 sections, the awns working their way into the mucous membrane, insinuating 

 themselves around the teeth, thus causing inflammation and deep ulcerating 

 sores, with the formation of pus. The teeth may consequently become 

 loosened and fall out. 



A Cheat or Brome Grass {Bromus tectorum) which is common in Utah, 

 parts of Colorado, and westward, produces similar injuries. 



The Needle Grass, common in the dry gravelly hills and sandy plains of 

 Northern Mississippi Valley has a fruit with a sharp pointed callus, with hairs 

 above the pointed callus projecting upwards. The sharp-pointed callus of the 

 "seed" enters tie skin, especially of sheep, where it produces an irritation 

 which is sometimes followed by death. This has sometimes been eaten with 

 forage, thus entering the intestinal tract, perhaps perforating it, causing death, 

 especially when they have pierced the walls of the intestines. Several allied 

 species as Black Oat {Stipa avenacea) produce similar injuries. The Western' 

 Needle Grass (Stipa comata), however, is less injurious than our Common 

 Needle Grass. 



