LAMSON-SCRIBNER AND MERRILL GRASSES OF ALASKA. 85 



Lemmas terminating in a straight or divergent awn which equals 

 or much exceeds the lemma in length. 



Awns divergent 8. A. spicatum. 



Awns straight. 



A stout grass with lemmas 10 to 13 mm. long 7. A. richardsonii. 



A slender grass with lemmas about 8 mm. long 6. A. caninum, 



1 . Agropyron dasystachyum (Hook.) Scribn. Bull. Torrey Club 10: 78. 1883. 

 Triticum repens dasystachyum Hook. Fl. Bor. Amor. 2: 254. 1840. 



Triticum dasystachyum A. Gray, Man. 602. 1848. 



A rigid, glabrous perennial 30 to 90 cm. high, with involute leaves and densely 

 pubescent spikelets; spikes 3 to 10 cm. long; glumes lanceolate, acuminate or short - 

 awned, fi to 9 mm. long, glabrous or nearly so; lemmas acute or short-awned, densely 

 pubescent; plants usually glaucous. 



In the upper Yukon and reported from the Chilkat region of southeastern Alaska. 

 It occurs in sandy soil from Saskatchewan to Wyoming and Michigan. 



Specimen examined: White River, Yukon Valley, Gorman 1151. Reported from 

 ( 'hilkat region by F. Kurtz/' 



2. Agropyron yukonense sp, now 



An erect, glabrous, not glaucous perennial, about 70 cm. high, with flat leaves and 

 crowded, densely pubescent spikelets with comparatively short glumes; sheaths 

 about equaling the internodes; ligule a narrow ring; leaf blades 10 to 20 cm. long, 

 rather thin in texture, 3 to mm. wide, flat, prominently nerved, glabrous beneath, 

 scabrous and thinly pilose above; spikes 8 to 10 cm. long; spikelets 10 to 15 mm. long, 

 the lower ones about equaling the nodes of the glabrous rachis, the upper ones more 

 crowded; glumes broadly lanceolate, acute or short -acuminate, subequal, 4 to 5 mm. 

 long, 1 to 2 mm. wide, strongly 3-nerved and pilose throughout; lemmas lanceolate, 

 acute, about 8 mm. long, 5-nerved, densely villous throughout; palea equaling the 

 lemma, narrow, truncate, slightly pilose and filiate on the keels. 



Type IT. S. National Herbarium no. 592342, collected July, 1900, Fort Yukon, 

 Alaska, by C. C. Georgeson (no. 22). 



Related to Agropyron dasystachyum (Hook.) Scribn., but distinguished by its green, 

 not glaucous, appearance, flat and rather soft, not involute, rigid, leaves, and com- 

 paratively short glumes, which are about one-half as long as the lower lemmas. 



3. Agropyron alaskanum sp. no v. 



A glabrous, erect perennial (iO to 90 cm. high, with pubescent nodes, usually flat 

 leaves and exserted narrow spikes; culms glabrous, nodes pubescent with short ap- 

 pressed hairs; sheaths mostly shorter than the internodes; ligule lacerate, about 1 mm. 

 long; leaf blades 10 to 25 cm. long, 4 to 7 mm. wide, flat or sometimes involute, scabrous 

 on both surfaces; spikes long-exserted, 6 to 14 cm. long, rather slender; spikelets 

 sometimes 2 at each node, 1.5 to 2 cm. long, 4 to G-flowered, exceeding the scabrous 

 internodes of the rachis; joints of the rachilla rather densely hispid with short stiff 

 hairs; glumes subequal, oblanceolate, 6 to 8 mm. long, 1.5 mm. wide, abruptly obtuse or 

 truncate, often slightly emarginate, bearing a stout awn 0.5 to 1 mm. long; lemmas 

 8 to 10 mm. long excluding the awn, lanceolate, hispid with short stiff hairs along the 

 sides, especially toward the base and on the callus, otherwise glabrous; awn straight, 

 2 to 3 mm. long; palea equaling the lemma, truncate, filiate on the nerves above, 

 glabrous toward the base. 



Upper Yukon . 



Type U. S. National Herbarium no. 592341, collected August 18, 1899, Circle City, 

 bv W. H. Osgood. 



Bot. Jahrb. Engler 19: 424. 1894. 



