AORDEUM GRAMINE.E 777 



produced beyond the flower, the lower empty glumes often reduced 

 to awns and forming an appar ent involucre around the spikelets. 

 Empty glumes rigid : the flowering ones rounded on the back, 5- 

 nerved at the apex, awned. Palets about equalling the glumes. 2 

 keeled. Stamens 3. Styles very short, distinct. Grain usually 

 adherent to the glume, hairy at the summit. 



H. jubatnm L. Sp. 85. Stems 10-30 inches high, erect, usually slen- 

 der smooth, sheaths usually shorter than the internodes: smooth : ligules 

 % line long, or less : leaves 1-5 inches long, 1-2 lines wide, erect, rough : 

 spikes 2-4 inches long: spikelets usually in threes, the central one, con- 

 taining a perfect flower ; lateral ones imperfect : empty glumes consisting 

 of slender rough awns l-2>£ inches long: flowering glumes of the central 

 spikelets 3-4- lines long: ecabrous at the apex, bearing a slender rough awn 

 l-2>£ inches long, the corresponding glume of the lateral spikelets short- 

 awned. On dry soil eastern Oregon to California, Pennsylvania and 

 Labrador, 



H. maritimum With. Arrang. 172. A smooth somewhat glaucous 

 annual: stems 6-18 inches long: sheaths about as long as the internodes, 

 the upper one inflated: ligules a mere ring: leaves 1-3 inches long, mostly 

 involute: spike subterete, scarcely exserted, 1-2 inches long, the rachis 

 breaking up when mature : spikelets an inch long, including the stiff awns : 

 empty glumes all lanceolate, not ciliate, one of each lateral spikelet a little 

 broader. Southwestern Oregon to California : introduced from Europe. 



H. Gcssoxeanum Pari. PI. Palerm. 244. Stems smooth often decum- 

 bent, 10-16 inches long : leaves thin, flat, finely pubescent, 1-3 inches long, 

 about 1 line wide: spikes subterete, exserted, 1-2 inches long, breaking 

 up when mature, empty glumes reduced to mere bristles, 6-8 lines long, 

 except the inner one to each lateral spikelet is twice as wide as the others : 

 flowering glumes oval, rough, 5-nerved, the awn 8 lines long. Oregon to 

 California, introduced from Europe. 



H. MDRINUM L. Sp. 85. A coarse decumbent annual : sheaths about 

 equalling the internodes: ligules very short: leaves 1)^-3 inches long, often 

 hairy: spike 2-4 inches long: often partly included in the upper sheath sli- 

 ghtly compressed, soon breaking up when mature: spikelets, including the 

 awns, 1-2 inches long, empty glumes of the middle spikelets lanceolate, 

 with ciliate margins: flowering glumes scabrous above, flat on the back, 

 8-10 lines long. In waste places, introduced from Europe. 



H. pusillum Nutt. Gen. i, 87. Stems 4-16 inches high, smooth: 

 sheaths loose, usually shorter, than the internodes, smooth, the upper 

 often enclosing the base of the spike: ligules very short: leaves 1)4-3 

 inches long : %-2 lines wide, smooth beneath, rough above : spike 1-3 

 inches long, spikelets usaally in threes : glume9 awned, the empty ones 

 scabrous: flowering glumes smooth, that of the central spikelets 3-4 lines 

 long : short-awned that of the lateral spikelets smaller. In dry soil Californ- 

 ia to Brit. Columbia Nebraska and Texas. 



H. nodosum L. Sp. ed 2, 126. H. pratense Huds. Stems 1-4 feet 

 high, often geniculate below, simple, smooth; sheaths shorter than the in- 

 ternodes : ligules % line long, truncate: leaves 1)^-6 inches long, 1-3 lines 

 wide, flat, rough: spike 1-4 inches long, flat, often arcuate: empty glumes 

 awn-like : flowering glumes of the central spikelets 3-4 lines long, bearing 

 an awn 3-6 lines long; that of the lateral spikelets much smaller. Common 

 in meadows, California to Alaska, Indiana and Texas also in Europe and 

 Asia. 



H. boreale Scribn. & Smith 1. c. 24. Stems slender, erect, smooth: 

 sheaths shorter than the internodes the lower ones pubescent: ligules very 



