GENERA OF GRASSES OF THE TTFr^O SJ/ATES. 101 



so that only the row of central spikelets on undi-sido 'oi tfe spike is 

 prominent. Naked barley is a kind of 2-rowed barley in which the 

 grain is free from the lemma and palea. Rice barley (H. zeocriton 

 L.), with spreading spikelets and divergent awns, is not grown in this 

 country and but sparingly in Europe. Beardless barley (H. vulgare 

 trifurcatum Wenderoth) (fig. 50, A) is a variety of 6-rowed barley 

 in which the awns are suppressed or converted into irregular short 

 lobes or teeth. Schulz 1 divides the cultivated barleys into two 

 groups. The first group, derived from II. spontomeum Koch, in- 

 cludes the 2-rowed varieties. The second group, derived from H. 

 ischnatherum (Coss.) Schulz, includes the 4 and 6 rowed varieties. 

 The glumes of Hordeum are thought by Schenck to be sterile spike- 

 lets or branchlets. (See footnote under Elymus, p. 93.) 



Three common species of Hordeum are annuals. One of these, 

 II. pusillum Nutt., with glumes broadened above the base, is a native 

 species. The other two, introduced from Europe, are common weeds on 

 the Pacific coast. In 77. murmum, L. a part of the glumes are ciliate ; 

 in II. gussoneanum Parl. the glumes are setaceous, smooth below. 

 Hordeum nodosum L. (fig. 51) is similar to PI. pusillum but differs 

 in being perennial and in having uniformly subulate glumes. This 

 species is abundant throughout the western half of the United States. 

 Another perennial species, H. jubatum L., called squirreltail grass 

 because of its soft brushlike spikes, is common in the Western States, 

 where it is not infrequently a troublesome weed in alfalfa fields. 

 This species is called foxtail in Wyoming, barley grass in Utah, and 

 tickle grass in Nevada. Hordeum, murinum^ mentioned above, is 

 called barley grass, foxtail, and wild barley in different localities. 



The species of Hordeum furnish forage during the early stages of 

 growth before the awns are produced. The mature spikes break up 

 into sharp-pointed joints that become a serious pest to stock. These 

 joints with the forwardly roughened awns work into the eyes and 

 nostrils of animals, causing inflammation. 



For a revision of the species of Hordeum found in the United 

 States, see Scribner and Smith, U. S. Dept. Agr., Div. Agrost. Bull. 

 4:23-25. 1897. 



41. LOLIUM L. 



Spikelets several-flowered, solitary and sessile, placed edgewise to 

 the continuous rachis, one edge fitting to the alternate concavities, the 

 rachilla disarticulating above the glumes and between the florets ; first 

 glume wanting (except on the terminal spikelet), the second outward, 

 strongly 3 to 5 nerved, equaling or exceeding the second floret ; lemmas 

 rounded on the back, 5 to 7 nerved, obtuse, acute, or awned. 



iMitt. Natf. Ges. Halle 1: 18. 1911. 



