18. Hordeum L. Barley 



Tufted annuals (frequently some perennial); inflorescences dense terminal 

 spikes; rachis abscising at the lower part of each node; spikelets in threes at each 

 node, the central one largest, the lateral ones reduced and pedicellate, 1 -flowered; 

 lemma contorted so that its back is abaxial; rachilla produced beyond the lemma 

 node as a point; glumes setaceous, produced into awns; lemmas cymbiform or 

 flatter, not keeled, obscurely 5-nerved, tapering into an awn. 



A genus of about 20 species of temperate regions. 



1. Awns 2-5 cm. long; spike nodding 1. H. jubatum. 



1. Awns mostly less than 1 cm. long; spike erect 2. H. brachyantherum. 



1. Hordeum jubatum L. Foxtail barley. 



Short-lived perennial or often behaving as a spring annual; culms basally de- 

 cumbent, mostly ascending, 30-65 cm. long; spikes 2-1 1 cm. long (not including 

 awns) and about 1 cm. thick (not including awns), nodding, dense, the rachis 

 abscising at the lower part of each node; spikelets in threes at each node, the 

 lateral ones pedicelled and with slightly smaller lemmas than the central one and 

 merely staminate; awns of the various glumes and lemmas not curved at maturity, 

 25-60 mm. long. 



Moist open ground, along ditches, in marshes and seepage areas, in shallow 

 water streams, and in waste places, often on alkaline or saline soils; a trouble- 

 some weed, especially in irrigated lands, in Okla. {Waterfall) and in Tex. Plains 

 Country and Trans-Pecos, in N. M. (Colfax, Taos, DeBaca, San Juan, Valencia 

 and McKinley cos.) and Ariz. (Coconino, Navajo, Apache and Maricopa cos.), 

 spring; w. U. S. e. to Plains States and as a weed e. to N. E. 



Var. caespitosum (Scribn.) Hitchc. has awns 1.5-3 cm. long. 



2. Hordeum brachyantherum Nevski. Meadow barley. Fig. 98. 



Perennial; culms tufted, erect or sometimes spreading, 1-5 dm. tall; blades 

 soft, usually glabrous, sometimes scabrous or shortly pubescent, 3-9 mm. wide; 

 spike slender, 2-8 cm. long; glumes all setaceous, 8-15 mm. long, those of the 

 central spikelet often scarcely longer than the palea; the rachilla prolonged, 

 usually extending beyond the middle of the palea; lateral spikelets pediceled, 

 the pedicels usually curved, the florets much-reduced. 



Wet meadows, flats, marshes, lakes or ponds and their borders, often in sub- 

 alkaline or saline soils, in N. M. (San Juan, Rio Arriba, Taos, McKinley and 

 Valencia cos.) and Ariz. (Coconino, Apache, Greenlee, Maricopa, Cochise and 

 Pima COS.); Nfld. to Alas., s. to N. M., Ariz, and Calif. 



19. Lolium L. 



Inflorescences elongate, terminal, lax spikes; axis sculptured with a niche for a 

 spikelet on one side of each internode, the axis remaining intact; spikelets 2-ranked, 

 solitary, each fitting within the niche of the internode, slightly if at all laterally 

 compressed, 5- to 20-flowered, all the florets perfect except the terminal one; 

 rachilla eventually abscising above the glume (s) and at the lower part of each 

 node; first glume obsolete or much reduced, adaxial when present (thus hidden 

 except on terminal spikelet), 3- to 5-nerved; second glume abaxial, strongly 5- to 

 7-nerved, membranous, obtuse; lemmas broadly ovate, 5- to 7-nerved, eventually 

 marginally revolute. 



A genus of perhaps 12 species in temperate Eurasia. 



1. Lolium perenne L. Ryegrass. Fig. 99. 

 Tufted perennial; culms 3-10 dm. long, mostly erect; spikes 7-25 cm. long, 



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