286 POISONOUS AND MECHANICALLY INJURIOUS PLANTS 



and Sitanion, respectively); needlegrass (Stipa); three-awn 

 {Aristida); and gramagrass (Bouteloua). 



Bromegrasses. — Downy bromegrass, sometimes called June 

 brome {Bromus teclorum); hairy bromegrass {B. villosus); and 

 red bromegrass {B. rubens) are the most troublesome species of 

 the genus. The causes of the injury inflicted by these plants are 

 much the same; the injurious effects, likewise, are practically 

 identical. At seed maturity the seed head breaks up readily. 

 As the animal grazes, the florets by means of the sharp calluses, 

 and later the long rough awns, penetrate and cause sores and in- 

 flammation of the skin, eyes, lips, teeth, tongue, throat, stomach, 

 and intestines. In the foothills of California red bromegrass in 

 the autumn is often very injurious to cattle, causing " big jaw " 

 and other complications. 



Barley and Squirreltail Grasses. — These closely related 

 grasses are probably the most destructive of the physically in- 

 jurious plants. In many parts of the West the awned spikelets, 

 especially those of squirreltail barley {Hordeum jubatum), (Fig. 

 109), are very injurious, particularly to sheep, causing severe 

 suffering and heavy losses of ewes and lambs (Fig. no). Losses 

 caused to lambing ewes by the feeding of hay containing mature 

 seed heads of squirreltail barley are sometimes very heavy. 



Humane considerations, as well as self-interest, should forbid the use of hay- 

 in which it [barley grass] makes up any large part of the bulk. This grass is 

 worth little for grazing; and when put up in hay it is dangerous. Fields and 

 meadows on which it grows would be improved by its destruction. No other 

 weed concerns the users and producers of hay for sheep-feeding so much as 

 squirreltail grass. It is dangerous as soon as it heads; when dried and fed in 

 considerable quantities it becomes obnoxious and destructive.^ 



The foregoing statement applies also to wall barley ( Hordeum 

 murinum). Pacific barley {H. Gussoneamim) . and to all species of 

 squirreltail grass {Sitanion). Of these, however, squirreltail 

 barley is the most troublesome. As many as 600,000 awns are 

 sometimes produced by a single plant. 



When a sheep's back, neck, and flanks are densely pierced by 



1 Fleming, C. E., and Peterson, N. F., "Don't Feed Fox-Tail Hay to Lambing 

 Ewes." Nev. Agr. Exp. Sta. Bui. 97, 1919. 



