7 



13. ERAGROSTIS LUTESCENS Scribn., sp. nov. 



A low, much branclied and densely ciespitose annual, 1-2 dm. high, with rather 

 short, flat leaves, and narrow, pale green or straw-colored panicles, 4-7 cm. 

 long. Cvilms glabrous. Sheaths loose or somewhat inflated, striate and 

 glabrous, or with a few short hairs at the throat ; ligule very short, ciliate ; 

 leaf-blade 2-5 cm. long, 2-8 mm wide, minutely scabrous above, very acute. 

 Panicle branches ascending or appressed, jiaked below. Spikelets narrowly 

 oblong, 2-3 mm. long, about \.~) mm. broad, 3 to many- (iTsually 10-12) 

 flowered. The empty glumes unequal, the first about 1 mm. long, the second 

 one-third longer and larger; flowering glumes obtuse, about 2 mm. long, 

 distinctly 3-nerved. 



This species is allied to Eragrostis purshii, but is more densely caespitose and is 

 at once distinguished by its narrow, yellowish-green panicles. 



Type specimens from sandy banks of Snake River, Almota, Washington, col- 

 lected by C. V. Piper, July 7, 1897, No. 2624. Number 4729 Prof. L. F. 

 Henderson found growing in sandy, moderately dry ground along the Platte 

 River, Platte, Southern Idaho, August 1, 1897, belongs to this species. 



14. ELYMUS ARENICOLUS Scribn. & Smith, sp. nov. 



A stout, erect, glaucous perennial, about 1 m. high, with numerous, tough, creep- 

 ing rootstocks. Culms terete, glabrous, 8-15 dm. high: nodes glabrous. 

 Sheaths striate, smooth, or the upper ones minutely strigose-pubescent, 

 nearly as long as the nodes and closely enveloping them; ligule coarsely 

 fimbriate, about 1 mm. long. Blades rigid, deeply furrowed on both sides, 

 smooth or very minutely strigose-pubescent on the back, strongly scabrous- 

 pubescent on the nerves, scabrous along the margins, 2-4 mm. wide, 2-3 

 dm. long, strongly involute and pungently pointed. Spike rather slender, 

 subflexuous, 1.5-2.5 dm. long, interrupted below ; rachis compressed, sparsely 

 hirsute along the margins and densely hirsute at the nodes. Spikelets single 

 or in pairs, lanceolate, comijressed, about ()-flowered; empty glumes subulate, 

 or nan-owly lanceolate, rigid, scabrous or sparsely hispid above, slightly 

 unequal, 7-10 mm. long, about half or less than half the length of the spikelet. 

 Flowering glumes rounded on the back, obliquely lanceolate, acute, sparsely 

 hirsute, especially toward the base, 5-nerved, mucronate- or sometimes awn- 

 pointed, the lowest about 10 mm. long. Palea a little shorter than its glume, 

 scarious along the margins, hispid scabrous on the keels, obtuse or emargi- 

 nate at the apex. 



Tyiie collected by A. B. Leckenby, at Suferts, Oregon, November 26, 1898. Grow- 

 ing in the sand dunes along the Columbia River. 



Other specimens examined are Nos. 466 and 468 Sandberg and Leiberg, Wash- 

 ington, 1893; No. 1176 Suksdorf, Rockland, Klickitat Co., Washington, 

 June 3, 1890. 



It differs from Elymus flavescens, with which it has been previously confounded, 

 in the narrowly lanceolate flowering glumes, which are less densely jmbes- 

 cent. Like Elymus flavescens it grows on the dryest sand dunes and is an 

 excellent sand binder. The bases of the culms are clothed with dead leaf 

 sheaths. 



F. LaMSON-ScR1J5NER, 

 Approved : Agvostoloijist. 



James Wilson, 



Secretary of AgricnUnre. 



Washington, D. C, February 15, 1809. 



O 



