50 GEAMINEAE (GRASS FAMILY) 



6-12 dm. high, with involute pointed leaves, and narrow greenish contracted 

 panicles 10-15 cm. long: sheaths pilose about the throat and on the margins: 

 glumes equal, with prominent green nerves, smooth or nearly so, subulate- 

 pointed, 8-9 mm. long; lemma pubescent, about 4 mm. long; the callus blunt 

 or subacute; awn usually twice bent, twisted to the second bend, minutely 

 scabrous, 25-30 mm. long. — At the lower altitudes throughout our range. 



12. Stipa neo-mexicana (Thurb.) Scribn.IJ. S. Dept. Agr. Div. Agros. Bull. 

 17: 132. 1899. Erect, rather stout and densely tufted, 3-9 dm. high, with in- 

 volute leaves, and narrow racemose panicles 8-10 cm. long: glumes nearly 

 equal, long-setaceous-pointed, 5-7-nerved, 3-4 cm. long; lemma 10-14 mm. 

 long, clothed with a close appressed pubescence; awn 8-12- cm. long, plumose- 

 hairy excepting near the base. — Extending into Colorado from the south. 



13. Stipa spartea Trin. Mem. Acad. St. Petersb. VI. 1: 82. 1831. Stout 

 and erect, with simple culms 6-10 dm. high, long narrow leaves and con- 

 tracted few-flowered panicles 10-20 cm. long: glumes subulate-pointed, 

 slightly unequal, 24-36 mm. long; lemma 16-20 mm. long, including the 

 barbed and very sharp-pointed callus, sparsely pubescent below and crowned 

 with a few short hairs; awn stout, twisted and pubescent below, twice bent 

 near the middle, 8-17 cm. long. Porcupine Grass. — Extending into our range 

 from the northeast. 



14. Stipa comata Trin. & Rupr. Agros. 3: 75. 1842. Rather stout, erect, 

 tufted, 3-9 dm. high, with mostly involute leaves and loosely-flowered panicles 

 16-24 cm. long: sheaths loose, the uppermost inflated and inclosing the base of 

 the panicle; ligule conspicuous, acute, 4-6 mm. long: glumes nearly equal, 

 long-attenuate-pointed, 18-24 mm. long; lemma 8-15 mm. long, including the 

 long, sharp callus, thinly pubescent; awn obscurely twice bent below, vari- 

 ously curled and twisted or only slightly flexuotis above, sparsely pubescent 

 below, 10-15 cm. long (5. Tweedyi Scribn. U. S. Dept. Agr. Div. Agros. Bull. 

 11: 47. 1898). Needle Grass. — New Mexico to British Columbia. 



18. ORYZOPSIS Michx. Rice Grass 



Usually tufted, the leaves flat or convolute and the inflorescence paniculate. 

 Spikelets l-flowered, broad. Glumes about equal, obtuse or acuminate; 

 lemma shorter or a little longer than the glumes, broad, bearing a terminal 

 awn which is early deciduous, the callus at base of the lemma short and obtuse, 

 or a mere scar. Stamens 3. Styles distinct; stigmas plumose. Grain oblong, 

 free; tightly inclosed in the convolute lemma. 



Leaves 1-2.5 mm. wide. 



Awn less than 2 riun. long .,,, ,, •!. O. jimcea. 



Awn more than 2 mm. long. 



Panicle narrow ........ .,2. O. exigua. 



Panicle open 3. O. miorantha. 



Leaves 4-8 mm. wide ......... 4. O. asperifolia. 



1. Oryzopsis juncea (Michx.) B. S. P. Prel. Cat. N. Y. 67. 1888. Erect, 

 glabrous^ slender, tufted, 15-60 cm. high, with erect involute leaves and nar- 

 row pamcles 2-5 cm. long: sheaths crowded below; leaves filiform, smooth or 

 scabnrous: spikelets 3-4 mm. long: glumes about equal, glabrous, whitish; 

 lemma pubescent with short appressed silky hairs; awn 2 mm. long or Icss.tt- 

 Colorado and northward and eastward. 



2. Oryzopsis exigua Thurb. in Wilkes U. S., Explor. Exped. 17: 481. 1874. 

 Slender, densely tufted, 15-40 cm. high, with filiform leaves, and narrow 

 simple few-flowered panicles 2-6 cm. long: spikelets 4-5 mm. long, on short 

 appressed branches: glumes nearly equal, abruptly mucronate-pointed; lemma 

 thinly pubescent; awn about 4_mm. long, twisted below, curved or geniculated 

 when mature. — In the mountains; Wyoming and northwestward. 



3. Oryzopsis miorantha (Trin. & Rupr.). Thurb. in Gray, Proc. Acad. Nat. 

 Sci. Phila. 1863: 78. Erect and slender, 3-7 dm. high, with narrow scabrous 

 leaves, and small-flowered spikelets in open panicles 8-16 cm. long: spikeletas 

 20-25 mm. long, much crowded at the ends of the branches of the panicles: 



