724 GRAMINEiE sporobolus 



POLYPOGON 



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

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

 leaves flat, 6-12 lines long: panicle ovoid or oblong, with loose capillary 

 branches: spikelets 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, i 

 eastern Washington to California, Colorado and Montana. 



$. gracillimus 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 

 apexj 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 ton 

 California. Y* 



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 gluihes : flowering glumes 3-nerved, mucronate 

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



S, fllifor mis 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. 



U POLYPOGOtf Desf. Fl. Atl. i, 66. (1798.) 



Annual or perennial grasses with flat leaves and numerous 

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

 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. ' prrain free, enclosed ip 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 : 



