246 A TEXT-BOOK OF GRASSES 



with cylindrical spikes and several setaceous glumes. All 

 the species mentioned except cultivated barley have an 

 articulated rachis that breaks up at maturity. 



Hordeum vulgare L. {H . sativum Jessen) . (Fig. 62.) Cultivated 

 barley. Annual; culms and leaves similar to those of wheat; auri- 

 cles prominent, as much as 5 mm. long, glabrous; spike densely- 

 flowered, usually 3 to 4 inches long, excluding the long awns or 

 beards, the rachis not disarticulating at matm-ity; spikelets in 3's 

 at each joint of the rachis; glumes about H inch long, narrow, the 

 upper half narrowed into an awn; lemma fusiform, about % inch 

 long, the upper portion narrowed into a very scabrous flat awn as 

 much as 6 inches long, the rachilla of the spikelet extended behind 

 the floret as a short hairy or scabrous pedicel lying in the furrow of 

 the palea. In most of the forms of barley the grain is tightly 

 inclosed in the lemma and palea. 



Beardless barley is a variety in which the awois are suppressed 

 and converted into irregular short lobes or teeth {H. vulgare tri- 

 furcatum Wenderoth). 



Schulz divides the cultivated barleys into 2 groups: (1) 

 Hordeum distichum, the 2-rowed barleys, which he refers 

 to H. spontaneum Koch as the wild prototype. (2) H. 

 polystichum, the many-rowed barleys, which he refers to 

 H. ischnatherum (Coss.) Schulz, as the wild prototype. 

 (Mitt. Natf. Ges. Halle 1 : 18. 1911.) 



269. Elymus L. — Wild rye. A moderate-sized genus 

 of temperate regions. Rachis continuous; spikelets usually 

 2 at each node; glumes in pairs in front of the spikelets 

 (the terminal spikelet having 2 opposite glumes) usually 

 subulate or awned. 



The related genus Sitanion differs in having an articu- 

 lated rachis. The glumes are usually subulate and 

 extended into long awns. Several species are found in the 

 western states. The mature joints of the disarticulated 

 rachis with the attached spikelets are injurious to grazing 

 animals, penetrating the ears, eyes and nostrils. 



