gastridium GRAMINE^E 729 



CINNA 



the central one excurrent at or below tbe middle as a strong bent awn 1-2 

 lines long : palet very small or none. Oregon to California. 



13 GASTRIDIUM Beauv. Agrost. 21. 



Panicle contracted into a somewhat loose tapering spike. 

 Spikelets 1-flowered. Empty glumes with an enlarged ventricose 

 shining base, very acute above, obscurely keeled, the lower longest. 

 Flowering glume less than i as long as the empty ones, minutely 

 hairy at base, very thin, truncate and dentate at the apex. Awn 

 slender, arising just below the apex, equalling or exceeding the 

 glumes. Palet equalling the flowering glume. Scales 2, linear, 

 as long as the ovary. Stamens 3. Stigmas 2, subsessile. 



G. adstrale Beauv. 1. c. Loosely cespitose: stems 6-24 inches high, 

 smooth, branching at the lower nodes, geniculate below: sheaths shorter 

 than the internodes, slightly roughened: ligules 2 lines long, lanceolate, 

 fringed: leaves flat, 2-5 inches long about 2 lines wide, scabrous on both 

 sides, pale green : panicle 3-6 inches long, very pale green, shining with a 

 satiny lustre; empty glumes about 2 lines long, very acute, slightly scab- 

 rous above, shining below: flowering glume hairy. On prairies, southern 

 Oregon to California: introduced from Europe. 



14 CINNA L. Sp. 5. 



Tall grasses with flat leaves and numerous spikelets in more or 

 less open panicles. Panicles flexuous, with spreading or erect 

 branches. Spikelets one-flowered, more or less flattened. Emp- 

 ty glumes lanceolate, acute, one-nerved, the lower shortest, the 

 upper equalling or slightly exceeding the flower. Flowering 

 glume 3-nerved, acute and awnless, or bearing a short awn or 

 seta just below the apex. Palet slightly shorter than the glume. 

 Scales 2, very short. Stamens 1, 2 or 3. Ovary oblong, smooth. 

 Styles 2, elongated. Stigmas plumose. Grain free, linear-oblong. 



C. pendnla Trin. Mem. Acad. St. Petersb. vi, 280. Stems usually 

 slender, erect, 2-6 feet high, smooth : sheaths shorter than the internodes, 

 sometimes slightly scabrous : ligules 1-2 lines long: leaves 4-10 inches long, 

 2-6 lines wide, scabrous : panicle 5-10 inches long, open, the capillary 

 branches mostly spreading, flexuous and often drooping, the lower 2-5 

 inches long: empty glumes 1% lines long, scabrous, acute, strongly hispid 

 on the keel : flowering glumes shorter than the outer ones, bearing a rough 

 awn \y^ lines long from the 2-toothed apex. In wet places, California to 

 Alaska and the Eastern States. 



15 MUHLENBERGIA Schreb. Gen. 44. 



Mostly perennial grasses with flat or convolute leaves and pan- 

 iculate inflorescence. Panicle contracted or open. Spikelets 

 one-flowered, very rarely two-flowered. Empty glumes hyaline 

 or membranous, acute, sometimes awned. Flowering glume 3-5- 

 nerved, obtuse or acute, or often produced into a capillary awn. i 

 Palet 2-keeled. Stamens 2 or 3. Styles distinct, with plumose 

 stigmas. Grain narrow, tightly enclosed in the glume. 



M, glomerata Trin. Unifl. 191. Stems 1-2 feet high, erect, usually 

 much branched, smooth : sheaths smooth, those of the stem shorter than 

 the internodes, those of the branches overlapping and often crowded: 



