42 GRAMINACEAE (GRASS FAMILY) 



DD. Spikelets either less than 7 mm. long or else lemma awned from the middle 

 or above it; spikelets 2 to many flowered; upper flower sometimes staminate or 

 abortive, the others perfect. 



E. Lemma keeled, obtuse or truncate, erose at tip, awn arising at or below the 

 middle. DESCHAMPSIA (p. 42) 



EE. Lemma convex, acute or shortly bifid, not erose, awn none or arising above 

 the middle. TRISETUM (p. 42) 



CC. Spikelets over i cm. long. 

 F. Perennial; awn of lemma between the teeth at apex; grain glabrous. 



DANTHONIA (p. 43) 

 FF. Annual or perennial; awn of lemma dorsal; grain hairy. AVENA (p. 43) 



DESCHAMPSIA (HAIR GRASS) 



Tufted. Spikelets 2-3-flowered, shining, in a terminal panicle. Glumes 

 keeled, the sides thinly scarious. Lemma membranous or nearly hyaline, 

 4-veined, obtuse or truncate, 2-4 toothed, awned ; awn fine, dorsal, arising 

 at or below the middle. (Honor of J. C. A. Loiseleur-Deslongchamps, a 

 French botanist.) The ist and 2d are good range grasses. 



A. Some of the flowers projecting beyond the glumes; awn very slightly or not at 



all projecting beyond its lemma. W. E. D. caespitosa (TUFTED HAIR-GRASS) 



AA. Flowers not projecting beyond the glumes; awn projecting beyond its lemma 



once the lemma length or more. 

 B. Perennial; glumes 3-6 mm. long; awn either less than 6 mm. long or straight, or 



both. 



C. Leaf blade flat; awn hardly or not at all projecting beyond the glumes; glumes 

 i-veined, 4.5-6 mm. long; plants 1.5-4 dm. high. W. C. E. 



D. atropurpurea (MOUNTAIN HAIR-GRASS) 



CC. Leaf blade rolled up; awn projecting beyond the glume at least } the glume 

 length; glumes 3-veined, 3-4 mm. long; plants 3-12 dm. high. W. C. E. 



D. elongata (SLENDER HAIR-GRASS) 

 BB. Annual; glumes 6-8 mm. long; awn 6-12 mm. long, geniculate. E. 



D. calycina (OAT-LIKE HAIR-GRASS) 



TRISETUM (FALSE OAT) 



Perennial, tufted. Spikelets 2-5-flowered, in a panicle. Glumes keeled, 

 the first the shorter, the second nearly as long as the spikelet. Lemma 

 keeled, acute or shortly bifid, awned; awn attached above the middle, 

 dorsal or at the base of the cleft (sometimes none in T. muticum), usually 

 twisted at base and more or less bent. Grain smooth, unfurrowed, inclosed, 

 free. (L. tres = 3, seta = a bristle; lemma has i awn and 2 sharp teeth.) 

 The 3rd and 5th ar good forage grasses. 



A. Glumes almost equal; lemma acute, awnless or with awn about i mm. long or 



less. 

 B. Glumes 6-7 mm. long; spikelets 3-flowered. E. 



T. muticum (BEARDLESS FALSE OAT) 

 BB. Glumes 3-5 mm. long; spikelets 2-flowered. E. 



T. wolfil (WOLF'S FALSE OAT) 



AA. Glumes unequal, the first -f as long as the second; lemma cleft at apex, awn 

 4-12 mm. long. 



