GRAMINEAE (GRASS FAMILY) 79 



2. Lolium temulentum L. 1. c. Culms ra-ther stout, 5-10 dm. high: spike- 

 lets 1-2 cm. long, often shorter than the intervals: glumes usually exceeding 

 the spikelet: florets short, obtuse. DARNEL. Adventive from Europe; some- 

 times a troublesome weed. 



62. AGROPYRON Gaertn. WHEAT GRASS 



Annual or perennial grasses with flat or involute leaves and terminal spikes. 

 Spikelets 3-many-flowered, sessile, single, and alternate at each notch of the 

 usually continuous rachis, the side of the spikelet turned toward the rachis. 

 Glumes empty; lemma rigid, rounded on the back, 5-7-nerved, usually acute 

 or awned at the apex; palets 2-keeled, the keels often ciliate. Stamens 3. 

 Styles very short, distinct; stigmas plumose. Grain pubescent at the apex, 

 usually adherent to the palet. Our species perennials. 



Caespitose, without creeping rootstocks or stolons. 



Rachis of the spike breaking up at maturity . . . 1. A. Scribneri. 



Rachis of the spike continuous. 



Spikelets strongly compressed, 8-20 mm. distant . . 2. A. spicatum. 



Spikelets nearly cylindrical, 3-10 mm. distant. 

 Basal culm leaves longer than the upper ones. 



Awns when present straight or but little divergent. 

 Spikes 8-20 cm. long. 



Flowering glumes awned . . . . . 3. A. caninum. 



Flowering glumes awnless or short-awned . . 7. A. tenerum. 



Spikes 3-10 cm. long . 4. A. violaceum. 



Awns widely spreading . . ' . . . . . 5. A. Bakeri. 



Basal culm leaves shorter than the upper ones . . 6. A. Gmelini. 



Culms from creeping rootstocks, not caespitose. 



Spikelets 7-1 3-flowered, compressed ...... 9. A. occidentale. 



Spikelets 3-8-flowered, subcompressed or nearly cylindrical. 

 Glumes half or less than half as long as the spikelets. 



Spikelets 16-20 mm. long, culms rather stout . . . 10. A. dasystachyum. 

 Spikelets 10-16 mm. long, culms slender . . . 11. A. subvillosum. 



Glumes about equaling or two thirds as long as the spikelets . 8. A. pseudorepens. 



1. Agropyron Scribneri Vasey, Bull. Torr. Bot. Club 10: 128. 1893. A 

 densely tufted perennial with ascending culms, 2-5 dm. high: leaves rigid, 

 attenuate-pointed, 2-3 cm. long, 2-4 mm. wide, the upper sheath thrice as 

 long as the blade; pubescent on both surfaces or smooth and glaucous: spikes 

 4-7 cm. long, readily breaking up at maturity, the joints falling with the 

 spikelets: spikelets 3-5 mm. distant, 3-8-flowered, the awns and glumes often 

 purplish: glumes linear-lanceolate or narrowly oblong, 5-8 mm. long, ex- 

 tended into an awn 7-25 mm. long, about 3-nerved, scabrous or hispid, little 

 scarious on the margins; lemma smooth or granulose-scabrous on the back 

 below, scabrous or hispid above, the strong mid-nerve extended into a spread- 

 ing or recurved hispid awn 15-35 mm. long. High mountains; Montana to 

 Colorado and Arizona. 



2. Agropyron spicatum (Pursh) Rydb. Mem. N. Y. Bot. Card. 1: 61. 1900. 

 A slender and often wiry, densely tufted, usually glaucous perennial, 3-9 dm. 

 high: leaves narrow setaceous, flat or involute, with scabrous margins and 

 smooth surfaces or minutely strigose-pubescent above; those of the culms 3-4, 

 4-20 cm. long, 1-3 mm. broad: spikes 6-14 cm. long: spikelets 4-12, remote, 

 8-20 mm. distant, erect or somewhat diverging, 3-6-flowered, 12-20 mm. long: 

 glumes smooth, 3-5-nerved, narrowly oblong to broadly linear, acute, rarely 

 obtuse or acuminate, prominently scarious-margined, 6-12 mm. long; lemmas 

 smooth on the back below, 5-nerved and rarely scabrous above, 7-10 mm. 

 long, terminating in a stout, diverging awn 12-24 mm. long; palet as long as 

 its glume or longer. (A. divergens Nees.) Dry, rocky soil and bench lands; 

 throughout our range and westward. 



2a. Agropyron spicatum Vaseyi (Scribn. & Smith) E. Nels. Bot. Gaz. 

 38: 378. 1904. Culms rigid and wiry, 3-5 cm. high: leaves 1-2 mm. wide; 

 those of the culms 3-8 mm. long: spikelets 48, 8-15 mm. long. Range of the 

 species. 



3. Agropyron caninum (L.) Beauv. Agrost. 102. 1812. An erect smooth 

 tufted perennial, 6-9 dm. high: leaves smooth beneath, usually rough above, 



