PIPER FLORA OF THE STATE OF WASHINGTON. 153 



SIT ANION. 



Glumes cleft or parted into 3 to many lobes; awns of lemmas 8 to 



10 cm. long 1. S. jubatum. 



Glumes entire or only 2-cleft or 2-parted. 

 Nerves of the glumes two. 



Glumes entire ; lemma glaucous, 1 cm. long 2. S. hrevifolium. 



Glumes or some of them bifid or 2-parted. 



Sheaths and upper surface of leaves glabrous. 



Leaves strongly involute 6. S. hasalticola. 



Leaves flat or tardily involute. 



Blades 5 to 7 mm. broad 5. S. laiifolium. 



Blades 2 to 5 mm. broad. 



Low plants; awns of lemmas 3 to 4 cm. long. 3. S. rigidum. 

 Taller; awns of lemmas 4 to 5 cm. long. . . 4. S. glabrum. 

 Sheaths and upper surface of leaves pubescent. 



Awns 2 to 3 times as long as lemma 7. S. ciliatum. 



Awns 4 to 5 times as long as lemma. 



Innovations many; culm leaves 7 to 12 cm. long. 8. S.hystrix. 

 Innovations few; culm leaves 2 to 6 cm. long. . 9. S. velutinum. 

 Nerves of the glumes 3 to 5. 



Leaves glaucous, 5 to 8 mm. broad 10. S. planifdium. 



Leaves green, 2 to 5 mm. broad 11. S. rubescens. 



1. Sitanion jubatum J. G. Smith, U. S. Dept. Agr. Div. Agrost. Bull. 18: 10. 1899. 

 Sitanion villosum J. G. Smith, U. S. Dept. Agr. Div. Agrost. Bull. 18: 11. 1899. 

 Sitanion stridum Elmer, Bot. Gaz. 36: 59. 1903. 



Type locauty: "Waits burg, Wash." Collected by Homer. 



Range: Washington to California. 



Specimens examined: Waitsburg, Horner 249, 573; Wawawai, Piper 2998; Pullman, 

 Piper 3021; Walla Walla, Shear 1602; Griffiths <fc CoUon 554; Waitsburg, Horner 574; 

 Spokane, Piper 2598; Pullman, Piper, July 28, 1899; Wawawai, Piper 3528, 3958, 3970, 

 3529; Clarks Springs, Kreager 99; Almota, Elmer 266. 



Zonal distribution : Upper Sonoran and Arid Transition . 



2. Sitanion hrevifolium J. G. Smith, U. S. Dept. Agr. Div. Agro.st. Bull. 18: 17. 1899. 

 Type locality: Tucson, Arizona. 



Range: Washington to Colorado and Arizona. 



Specimens examined: Falcon Valley, Suksdorf 519S, July 16, 1905. 



3. Sitanion rigidum J. G. Smith, U. S. Dept. Agr. Div. Agrost. Bull. 18: 13. 1899. 

 Type locality: "Cascade Mountains, Washington." Collected by Allen. 

 Range: Washington to California and Wyoming. 



Specimens examined: Olympic Mountains, Flett 119, 832; Goat Mountains, Allen 178; 

 Mount Stuart, Elmer 1145; Mount Chapaca, Elmer, August, 1897; Blue Mountains, Horner 

 579; without locality, Vasey 454. 



Zonal distribution; Arctic. 



4. Sitanion glabrum J. G. Smith, U. S. Dept. Agr. Div. Agrost. Bull. 18: 14. 1899. 

 Type locality: "Near Crystal Spring, Caso Mountains, California." 



Range: Washington to California. 



Specimens examined; Olympic Mountains, Elmer 1904; Mount Rainier, Piper 1952; 

 Mount Adams, Henderson, August, 1892; head of Twenty-five-mile Creek, Gorman 824. 

 Zonal distribution: Arctic. 



