GRASS FAMILY 183 



11. A. flexuosum Piper. Culms 2 to 3 feet high, slender, witlioiit rhizomes; 

 sheaths smooth ; blades short, tiat or loosely iuvolute ; spike 3 to 4 inches long, 

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

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

 a slender spreading awn \-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. (Warner Mts., Gri/Jifhs rf- Hinder 468) to Wash- 

 ington and Idaho. 



Eefs. — Agropyron flexuosum Piper, Proc. Biol. Soc. Wash. IS: 149. 1905. Sitanion 

 flexuosum Piper, Erythea 7: 99. 1899. 



12. A. scribneri Vasey. Culms ascending or spreading, i/> to 11/4 feet high ; 

 blades short, tlat, rather thin, mostly basal; spike shoi't 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 i/o 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 ]\I()utaua 

 and south to Arizona and New Mexico. 



Ref.— Agropyron scribneri Vasey, Bull. Torr. Club 10: 128. 1883. 



13. A. pringlei Hitclic. n. comb. Culms 1 to II/2 feet high ; blades usually 

 flat, 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, Leiherg 5244; Carson Pass, Brewer 2118; Mt. Tallae, Hitchcock 3152; 

 Pyramid Peak, Ball ^ Chandler 4718; Sequoia Nat. Park, HitchcocTc 3385; Little Kern River, 

 Piirpus 5515. 



Refs. — Agropyron pringlei Hitehc. A. gmelini Scribn. & Smith var. pringlei Scribn. & 

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

 Pringle. 



68. HORDEUM L. Wild Barley. 

 Spikelets 1-tlowered, 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 liemi- 

 spheres. (The ancient Latin name for barley,) 



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



Plants annual. 



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



(Humes not ciTate. 



Glumes of fertile spikelet d'lated iiliovc the base ' 2. H. pu.siUum. 



(ilumes not dilated. 



Glumes very scabrous 3. H. nodosum.. 



Glumes glabrous or m'nutely scnlirous 4. H. r/ussoneanum. 



