44 POACEAE. 



Agrostis exarata Trin. Perennial, tufted, the stems 30-90 cm. tall; leaves 

 erect, the blades flat, 2-6 mm. broad, 5-10 cm. long, scabrous, the upper 

 distant from the panicle; panicle strict, pale green, spike-like or interrupted, 

 the short branches appressed and spikelet-bearing to the very base; glumes 

 2.5-3.5 mm. long, usually scabrous on the back. 



Variable and very common. 



Agrostis rossae Vasey. Tufted, 10-20 cm. high; leaves mostly basal, 

 2-5 cm. long, 1-2 mm. broad, flat or folded; panicle narrow, erect, 3-6 cm. 

 long, green or purple; glumes 2 mm. long, not scabrous. 



In alpine meadows, common. 



Agrostis howellii Scribn. Stems 40-60 cm. high; blades very long, 3-5 

 mm. wide; panicle very loose; spikelets clustered near the tips of the branches; 

 glumes acuminate, equal; lemma acute, awned from the back. 



In rocky places in the Columbia Gap. 



Agrostis hyemalis (Walt.) BSP. Annual, tufted, 15-90 cm. tall; leaves 

 flat or involute, narrow, very scabrous; panicle very loose, 15-30 cm. long; 

 branches in whorls of 2-12, capillary, 5-15 cm. long, branched above the middle 

 and spikelet-bearing only near the tips. 



In moist places, common. 



Agrostis pregonensis Vasey. Stems slender, 60-80 cm. high; blades 

 narrow; panicle pyramidal, nodding, open, the branches capillary; glumes 

 subequal, scabrous on the keel; lemma shorter, obtuse, awnless. 



In marshes, rare. 



Agrostis melaleuca (Trin.) Hitchc. Perennial from creeping root- 

 stocks, not tufted; stems erect, 30-50 cm. high, leafy; leaf blades 1-3 mm. 

 wide; panicle oblong, 5-15 cm. long; glumes subequal, copper-colored, 2.5-3 

 mm. long, acute, smooth; lemma nearly as long, bearing from the middle of 

 the back a short straight scarcely exserted awn; palea minute or wanting. 



In sphagnum marshes, Garibaldi, Oregon, Hitchcock; north to Alaska. 



Agrostis longiligula Hitchc. Stems tall, 60-80 cm. high; leaf blades 

 flat, scabrous, 3-4 mm. wide; ligule 5-6 mm. long; panicle purple, rather 

 dense, 10-18 cm. long; glumes 3-4 mm. long, acute, scabrous on the keel, 

 hispidulous on the back, the upper a little shorter; lemma 2.5 mm. long, 

 scabrous on the nerves, bearing a bent awn 2.5 mm. long; palea minute. 



Alaska and Vancouver Island, Macoun, to northern California. 



65. HOLCUS. 



Annual or perennial grasses with densely-flowered terminal 

 panicles; spikelets deciduous, 2-flowered, the lower flower perfect, 

 the upper staminate; glumes membranous, keeled, the lower 1- 

 nerved, the upper 3-nerved and often short-awned; lemmas 2, 

 papery, that of the upper floret bearing a bent awn; palea 

 narrow; grain oblong, free, enclosed in the lemma. 



Holcus lanatus L. Velvet-grass or Mesquite. Perennial; the whole plant 

 downy with pale pubescence; stems erect, 30-90 cm. high; leaf blades flat, 

 rut her broad and short; sheath loose, shorter than the internodes; panicle 

 pale purplish, 5-10 cm. long, rather densely-flowered, the branches in twos 

 or threes; spikelets 4-6 mm. long; upper glume short-awned near the apex; 

 lemma of the staminate flower with a hook-like awn. 



Abundantly introduced in fields and waysides. 



