GRAMINEAE (GRASS FAMILY) 49 



3. Stipa speciosa Trin. & Rupr. Agrostidea 3: 45. 1842. Erect and rather 

 stout, densely tufted, 3-6 dm. high, with long narrow radical leaves, and erect 

 contracted panicle 12-16 cm. long: glumes 16-18 mm. long, nearly equal, 

 acuminate, hyaline, the first 3-, the second 5-7-nerved; lemma silky-pubescent, 

 10-12 mm. long; callus short, curved; awn 3-4 cm. long, geniculate below the 

 middle, the twisted portion plumose with white silky hairs 3-6 mm. long. 

 Extending into Colorado from the southwest. 



4. Stipa Scribneri Vasey, Bull. Torr. Bot. Club 11: 125. 1884. Stout, erect 

 and smooth, 4-8 dm. high, with rather long, narrow, involute-pointed culm 

 leaves, and contracted panicles 12-16 cm. long: uppermost culm-leaf almost 

 equaling the panicle: glumes unequal; the first 12-14 mm. long; the second 

 about 10 mm. long, both 3-nerved, acuminate; lemma &-10 mm. long and 

 crowned with a tuft of rather long hairs; awn once or twice bent, twisted in 

 the lower half, 16-18 mm. long. Southern Colorado and New Mexico. 



5. Stipa Lettermanii Vasey, Bull. Torr. Bot. Club 13: 53. 1886. Slender 

 and glabrous, with wiry culms 2-6 dm. high, filiform leaves, and slender, few- 

 flowered, interrupted, shortly exserted panicles 5-15 cm. long: glumes narrow, 

 more or less hyaline, equal or nearly so, smooth or very minutely scabrous on 

 the back, 7-9 or rarely 10 mm. long; lemma 4-5 mm. long, pilose, the hairs 

 spreading and forming a more or less distinct crown at apex ; the callus acute. 

 In dry soil throughout our range. 



6. Stipa occidentalis Thurb. in Bot. King's Exp. 380. 1871. Slender, erect 

 and tufted, 3-8 dm. high, with narrow setaceously pointed leaves and erect, 

 contracted panicles 8-16 cm. long: glumes about equal, thin-membranous and 

 carinate above, 10-12 mm. long; lemma clothed with a thin, short pubescence, 

 5-6 mm. long; awn twice bent, twisted to the second bend, pubescent or sub- 

 plumose on the lower half, the upper half minutely scabrous, 25-35 mm. long. 

 Extending into Wyoming from the far west. 



7. Stipa columbiana Macoun, Cat. Can. PI. Part IV. 191. 1888. Erect and 

 slender or rather stout, 4-9 dm. high, glabrous or the culms minutely pubescent 

 below the nodes, with long narrow leaves and usually purplish panicles 

 15-20 cm. long: glumes somewhat unequal, 7-9 mm. long, usually more or 

 less purplish; lemma 4-5 mm. long, thinly pilose; the callus short and acute; 

 awn usually twice bent, twisted to the second bend, minutely scabrous, 15- 

 25 mm. long. [S. minor (Vasey) Scribn.] Common in the mountains through- 

 out our range. 



8. Stipa Williamsii Scribn. U. S. Dept. Agr. Div. Agros. Bull. 11: 45. 1898. 

 Erect and rather stout, 7-9 dm. high, with long flat leaves and strict panicles 

 10-22 cm. long: culms pubescent at least near the nodes: sheaths softly pubes- 

 cent, at least the lower ones: glumes nearly equal, about 9 mm. long, smooth 

 or very minutely scabrous; lemma about 6 mm. long, clothed with appressed 

 hairs, the callus sharply pointed; awn usually twice bent, twisted to the 

 second bend, minutely scabrous, 2-3 cm. long. Infrequent; Wyoming, 

 Montana, and eastern Idaho. 



9. Stipa Nelsonii Scribn. U. S. Dept. Agr. Div. Agros. Bull. 11: 46. 1898. 

 Rather stout, glabrous, 6-9 dm. high, with long, narrow leaves: panicles strict, 

 10-25 cm. long, pale and of a silvery and comose appearance: glumes narrow, 

 thin and hyaline excepting the nerves which are quite prominent, smooth or 

 minutely scabrous on back, the first about 10 mm. long, the second a little 

 shorter; lemma 6-7 mm. long, clothed with soft, silky hairs; the callus rather 

 acute; awn usually twice bent, twisted to second bend, scabrous, 35-40 mm. 

 long. Throughout our range. 



10. Stipa Vaseyi Scribn. U. S. Dept. Agr. Div. Agros. Bull. 11: 46. 1898. 

 Stout, erect, 8-18 dm. high, with long flat leaves and erect, densely flowered 

 panicles 20-45 cm. long: sheaths usually pilose at the throat and often sparsely 

 so on the margins: glumes nearly equal, about 10 mm. long, firm in texture, 

 minutely but distinctly scabrous on the back; lemma pubescent, 6-7 mm. 

 long; the callus acute; awn scabrous, usually twice bent, twisted to the second 

 bend, 25-35 mm. long. Colorado and southward. 



11. Stipa viridula .Trin. Gram. Suppl. 39. 1836. Erect and rather stout, 



ROCKY MT. BOT. 4 



