GRASS FAMILY 183 



11. A. flexuosmn Piper. Culms 2 to 3 feet high, slender, without rhizomes ; 

 sheaths smooth; blades short, flat or loosely involute; spike 3 to 4 inches long, 

 flexuous, long-exserted, the rachis disarticulating; spikelets sometimes in 

 pairs; glumes subulate or narrowly lanceolate, mostly 2-nerved, narrowed into 

 a slender spreading awn V 2 to 1 inch long; lemmas 4 lines long, smooth and 

 rounded below, 5-nerved and somewhat scabrous above, tipped with a slender 

 spreading awn about an inch long. 



Mountain slopes, Modoc Co. (AVarner Mts., Griffiths & Hunter 468) to Wash- 

 ington and Idaho. 



Kefs. AGROPYROX FLEXUOSUM Piper, Proc. Biol. Soc. Wash. 18: 149. 1905. Sitanion 

 flcxuosum Piper, Erythea 7: 99. 1899. 



12. A. scribneri Vasey. Culms ascending or spreading, Vs to 1% feet high ; 

 blades short, flat, rather thin, mostly basal; spike short and thick, 1 to 2 inches 

 long, readily disarticulating at the joints; spikelets rather closely imbricated, 

 somewhat divergent, about 5 lines long, few-flowered; glumes narrow, rigid, 

 2-nerved, gradually narrowed into a horizontally spreading awn % to % inch 

 long; lemmas nerved toward tip, terminating in awns similar to those of the 

 glumes but somewhat longer. 



Rocky slopes, mostly above 9000 feet, Mt. Dana (Congdon in 1898) to Montana 

 and south to Arizona and New Mexico. 



Ref. AGROPYROX SCRIBXERI Vasey, Bull. Torr. Club 10: 128. 1883. 



13. A. pringlei Hitchc. n. comb. Culms 1 to iy 2 feet high ; blades usually 

 tiat, short; spike 2 to 4 inches long, not disarticulating, the spikelets falling 

 from the rachis; glumes lanceolate, 3 to 5-nerved, ending in a short straight 

 awn ; lemmas ending in stout horizontally spreading awns about % inch long. 



Gravelly slides and rocky slopes at 7000 to 12,000 feet elevation in the Sierra 

 Nevada ; also in Wyoming. 



Locs. Webber Lake, Leiberg 5244; Carson Pass, Brewer 2118; Mt. Tallac, Hitchcock 3152; 

 Pyramid Peak, Hall $ Chandler 4718; Sequoia Nat. Park, Hitchcock 3385; Little Kern Eiver, 

 Purpus 5515. 



Refs. AGROPYROX PRIXGLEI Hitchc. A. gmelini Scribn. & Smith var. pringlei Scribn. & 

 Smith, U. S. Dept. Agr. Div. Agrost. Bull. 4: 31. 1897, type from above Summit Valley, 

 Pringle. 



68. HORDEUM L. WILD BARLEY. 



Spikelets 1-flowered, 3 together at each joint of the rachis, the middle one 

 sessile and perfect, the lateral usually pediceled, often reduced to awns. Glumes 

 equal, rigid, narrow-lanceolate, subulate or setaceous, usually elongated and 

 awn-like, the 3 pairs simulating an involucre around the central perfect floret. 

 Rachilla prolonged behind the palea as an awn, sometimes with a rudimentary 

 floret. Lemma of central floret obscurely 5-nerved, tapering into an awn. 

 Palea with its back toward the rachis. Cespitose annuals or perennials with 

 dense terminal bristly spikes disarticulating at maturity, the joints falling with 

 the spikelets attached. Species about 16, temperate regions of both hemi- 

 spheres. (The ancient Latin name for barley.) 



Plants perennial ; awns as much as 2 inches long 1. H. jubatum. 



Plants annual. 



Glumes or some of them ciliate 5. H. murinum. 



Glumes not cil : ate. 



Glumes of fertile spikelet delated above the base 2. H. pusillum. 



Glumes not dilated. 



Glumes very scabrous 3 - # nodosum. 



Glumes glabrous or nrnutely scabrous 4. H. gussoncanum. 



