724 GRAMINE^E SPOROBOLUS 



POLYPOGON 



8. Bolanderi Vasey Bot. Gaz. xi, 337. Stems slender, about 1 foot 

 long, decumbent below, smooth : ligules short and obtuse : leaves narrow, 

 flaccid, the radical ones about 6 inches long : cauline ones similar, 1-2 

 inches long: panicle 2-3 inches long, open, lax, its lower branches in twos 

 or threes, filiform, 12-18 lines long: empty glumes unequal, 1-nerved; 

 flowering glume exserted, 5-nerved, softly pubescent on the nerves below. 

 Collected at Multnomah Falls Oregon by Dr. H. N. Bolander. 



S. confusus Vasey Beal Grasses N. Am. ii, 294. Stems slender, 

 tufted, branching, 3-8 inches high from an annual root : sheaths loose : 

 leaves flat, (M2 lines long : panicle ovoid or oblong, with loose capillary 

 branches: spike lets less than a line long, smooth, on capillary pedicels 3-4 

 times as long : empty glumes subequal, obtuse or retuse at the apex ; flow- 

 ering glume but little longer, barely acute. On sandy banks of streams, 

 eastern Washington to California, Colorado and Montana. 



S. gracillimns Vasey Vilfa gracillima Thurber. Stems capillary, 

 smooth, much branched at base, forming small dense tufts, 3-12 inches 

 high, the leafy portion about 2 inches high : sheaths equalling the inter- 

 nodes, smooth, with hyaline margins: ligules about a line long, obtuse and 

 lacerate: leaves 3-6 lines long, less than a line wide, flat, involute at the 

 apex, very minutely scabrous on the upper side and margins : panicle long- 

 exserted, narrowly linear, few-flowered, interrupted below, its branches 

 in twos or threes, appressed: spikelets about 1 line long: empty glumes 

 subequal, membranaceous, very obtuse, distinctly 1-nerved, mucronate or 

 erose-dentate at the apex : flowering glume 3-nerved, mucronate or tipped 

 with a small awn. Edge of marshes in the high mountains, Oregon to 

 California. 



S. simplex Scribn. U. S. Dept. Agr. Bull. 11, 48. A densely cespi- 

 tose leafy annual, 2-6 inches high: stems slender, smooth: lower sheaths 

 loose, longer than the internodes : ligules a line or more long : leaves flat, 

 1-2 inches long, scabrous on the margins, very rough near the rigid apex : 

 panicle linear, 1-2 inches long, its scabrous branches erect : spikelets 1 line 

 long: empty glumes subequal, obtuse or truncate, scabrous on the back above, 

 flower twice as long as the glumes : flowering glumes 3-nerved, mucronate 

 pointed, scabrous above. In moist places, Idaho to California and Colorado. 



S. flliformls Scribn. 1, c. Bull 17, 173. A very slender densely tufted 

 annual, 3-12 inches high : stems filiform and scape-like, with very short 

 internodes below: leaves filiform, 6-12 lines long: panicle linear, long-ex- 

 serted spikelets less than a line long: empty glumes subequal, obtuse and 

 mucronate, flowers about twice as long as the empty glumes ; flowering 

 glume acute, 3-nerved, scabrous on the midnerve. In moist soil in the high 

 mountains, Washington to California and Utah. 



11 POLYPOGON Desf. Fl. Atl. i, 66. (1798.) 



Annual or perennial grasses with flat leaves and numerous 

 flowers in spike-like panicles. Spikelets 1-flowered. Glumes 3, 

 the 2 outer empty, nearly equal, compressed, 1-nerved and bear- 

 ing a long awn at or below the apex. Flower much shorter than 

 the empty glumes, without manifest callus and naked at base. 

 Flowering glume hyaline, broad, 1-nerved, truncate, toothed, 

 awned at the apex: scales 2, falcate, entire, as long as the ovary. 

 Stamens 3, with small anthers. Styles short, with long feathery 

 stigmas. Grain free, enclosed in the glume and palet. 



P. Monspeliensis Desf. 1. c. 67. Stems 6-30 inches high erect from a 

 procumbent geniculate base, often branching from the lower nodes : sheaths 

 smooth usually shorter than the internodes : ligules 2-3 lines long, obtuse : 



