SPERMATOPHYTA—GRAMINEAE— GRASSES 359 



sistent; flowering glume deciduous, generally bearing a twisted awn on the 

 back between the two acute teeth at the apex ; rachis and base of flower often 

 bearded ; stamens 3, style short and distinct ; grain oblong, linear, grooved on 

 one side invested by the palet. About SO species in temperate regions. The 

 cultivated Oats {Avena saliva) is the best known representative of the genus 

 and has long been used for food for man and animals. Several native species 

 produce good forage. 



Avena fatua L. Wild Oats 



An erect, glabrous annual, 3-S feet high, with flat leaves and spreading 

 panicles of large, nodding spikelets ; spikelets 2 to 4-flowered, with empty glumes 

 54-1 inch long and pubescent; flowering glumes 6 to 9 lines long; awns nearly 

 twice as long as the spikelets. Wild oats is highly esteemed as a forage plant 

 on the Pacific Coast, especially California. 



Distribution : Native to Europe but now abundant in grain fields of the 

 Rocky Mountains, the Dakotas, Minnesota, and the Pacific Coast. 



Injurious properties. Bezoars are sometimes produced by the common oat 

 and Dr. Harz thinks it is a dangerous food material because it favors the 

 development of these "hair balls." The barbed and awned seed of the wild 

 oat may probably sometimes also lodge in the mouth and produce inflammation 

 or other results of mechanical injuries. 



Avena saliva, L. Common Oats 



A well known erect annual, 2-4 feet high, with flat leaves and expanded 

 panicles of rather large, pendulous, and, usually, 2-flowered spikelets. Lower 

 florets sometimes awned. 



Distribution. Widely cultivated in Europe, North America, Asia, and in 

 all temperate regions. Commonly cultivated in Northern United States, Can- 

 ada, and the Pacific Coast. The species is native to eastern temperate Europe, 

 and western Asia, although the wild form has not been found. According to 

 some authors, cultivated oats originated from wild oats Avena fatua. Thi& 

 is very doubtful. 



Injurious properties. Harz reports the occurrence of phytobezoars in horses 

 which had been fed oats straw. These bezoars in their origin and structure 

 are similar to those occurring from feeding on cacti and the crimson clover 

 referred to elsewhere. 



9. Bro-mus, L. 



Spikelets S to many-flowered, panicled; glumes unequal, membranaceous; 

 lower glume 1-S nerved; flowering glume either convex on the back or com- 

 pressed-keeled, S-9-nerved, awned or bristle-pointed from below to the groove 

 of the oblong or linear grain; stamens 3; styles attached below at the apex of 

 the ovary. Coarse grass with large spikelets at length drooping on pedicels 

 thickened at the apex. About 40 species, of which Beal lists 27 as either native 

 or introduced into the U. S. 



Bromus tectorum, L. Awned Brome Grass 



A slender, erect, leafy annual, 7-2S inches high, with narrow, softly 

 pubescent leaves and open, nodding panicles, 3-7 inches long; spikelets each S-8 

 flowered, with unequal, acuminate-pointed, hairy, empty glumes, and rough or 



