366 MANUAL OF POISONOUS PLANTS 



12. Hordeum, L. Barley. 



Annual or perennial grasses with flat leaves ; cylindrical spikes ; spikelets 1- 

 flowered, with an awl-shaped rudiment on the inner side, 3 at each joint of 

 the rachis of a terminal spike, the lateral ones usually imperfect or abortive 

 and with a short stalk, empty glumes side by side in front of the spikelets, 

 forming a kind of involucre; flowering glume and palet herbaceous, the former 

 long and awned from the apex; stamens 3; styles very short; grain usually 

 oblong and adherent to the palet; spike often separating into joints. 



About 20 species widely distributed in both hemispheres. Of the Barleys, 

 the 2-rowed barley {Hordeum distichum) and the 4-rowed barley (H. vulgare) 

 are well known in cultivation, being used for malting purposes and occasionally 

 in medicine. The awns of cultivated barleys produce mechanical injuries to 

 stock. Several members of the genus are very troublesome weeds. 



Four-Rowed Barley. Annual, 2-3 feet high, smooth; leaves linear-lanceo- 

 late, keeled, nearly smooth; sheaths striate, smooth, auricled at the throat; 

 ligule very short ; spikes 3-4 inches long, somewhat 4-sided ; rachis flattened, 

 pubescent on the margins; spikelets with 1 perfect floret; empty glumes, narrow- , 

 ly linear, pubescent, terminating in a slender awn ; flowering glume S-nerved, 

 scabrous near the apex, long-awned; awn flattened, keeled, somewhat 3-nerved, 

 serrulate on the margins. 



The cereal is without doubt one of the most ancient of cultivated plants. 

 It is supposed to have originated from H. spontaneum Koch, which grows wild 

 in Asia Minor and Caucasian countries to Persia and Beloochistan as well 

 as in Syria and Palestine. 



Hordeum jubatum, L. Squirreltail Grass. 



An annual or winter annual from 6 inches to 2 feet high producing fibrous 

 roots, forming solid and compact bunches ; leaves not unlike those of blue 

 grass, but paler in color, from 2t4 inches in length, margins scabrous; flowers 

 in dense spike from 2-4 inches long, pale green or purplish in color, consisting 

 of a number of 1-flowered spikelets, 3 occurring at each joint, 1 being perfect 

 (bearing stamens and pistil), 2 others awl-shaped, and borne on short stalks, 

 1 sterile spikelet occurring on each side of the perfect flower which bears a 

 long awn; at each joint will be found 6 empty, long-awned glumes, spreading 

 at maturity which give to the plant its bristly appearance; when mature, the 

 spike breaks up into joints consisting of the rudimentary spikelets and a perfect 

 flower, so that each joint has 1 "seed," the number of seeds in the spike varying 

 from 35 to 60. A single cluster of plants may therefore produce from 300 to 

 2000 mature seeds. The plant has a wonderful capacity for "stooling." From 

 a single plant as many as forty spikes may be produced and the number often 

 no doubt exceeds this. 



Distribution. It is found in marshes, in moist sand along the sea shore, 

 and near the northern lakes. Its present distribution is from Nova Scotia to 

 New Brunswick, along the Atlantic coast, Maine to Maryland and westward to 

 the region of the Great Lakes, Minnesota, Saskatchewan and the Mackenzie 

 river, the Dakotas, Iowa, Nebraska and the Rocky Mountain region, south to 

 Texas, California and southern Mexico. It is also reported from Europe and 

 Siberia. 



Originally it was chiefly distributed in the Rocky Mountain region occur- 



