de 
T. 
8. 
8 
3 
9. 
10. 
El: 
26 
Culm >. 6 or 7, e e glumes — HTR or os pointed...... A. arizonicum. 
Culm s3 or 4, em glumes acute or obtu A. divergens. 
Basal culm leaves ee Iban de ON Pers A A. gmelini. 
. Basal culm leaves longer than the upper. -.-...---.------------------------ 9 
otim wi EN /,, ͤõͤ d E S 10 
Flower z glu ,,. coc ese 2h oes 11 
Culms stout, d spikes erect.. „ 1 
ulms more or less geni Pa S ascending; spikes nodding.. .A. caninum. 
Spikes stont, 1 to 3 inches long, empty and flowering glumes broadest abov 
middl pats 1. violaceum. 
3 pos slender, 2 to 8 inches long, empty and flow ering glumes cet belov 
11 
middle ter sari: 
12. Empty glumes 9- to ye sciens „ 4. junceum. 
E A c de. odeur nce eire 13 
13. Apex of the ENR pone Obtuse OF UnA A oes eos cae ees 14 
13. Apex of the flowering glume acute or acuminate..........-.---.------------ 15 
14. Culms geniculate, empty glumes one-fourth shorter than the spikelet. A. campestre. 
14. Culms erect, empty glumes half as long as the spikelet, truncate b- 
bow A. glaucum. 
15. Spikes distinctly 4-angled, rachis artieulated A. tetrastachys. 
15. Spike not distinctly 4- -angled, A )QQ—Q—Q— ae 16 
16. Flowering glume with a geniculate divergent awn A. albicans. 
16. Flowering glume with a straight awn or awnless...... 17 
17. Spikelets compressed, ovate, acute, divergin ggg A. spicatum. 
17. Spikelets narrow, subcompressed, or visi ra Sm acute or obtuse........- 18 
18. Flowering glumes densely re or lanate A. dasystachyum. 
Jd Flowermg flames: f eaa aa 19 
19. Leaves flat, smooth on the back; pa et A es nerves above....... A. repens. 
Leaves »eeoming involute,scabrons on the Bk es 20 
20. Leaves strigose-pubescent abov dec spike elongated............... 4. lanceolatum. 
20. Leaves seabrous above, spike compact. 3 
21. Empty glumes less than half as long Pr 9 spikelet A. riparium. 
21. Empty glumes about equaling the spik --------. A. pseudorepens. 
A. Cespitose, without creeping ene or stolons. 
achis of the spike continuous. 
Spikelets strongly com pices remo 
ied glumes one-half as long as the orta or less. 
Agropyron divergens Nees in Steud. Syn. Plant. Gram., 347. This species has been 
referred by py authors to the Siberian 4. strigosum ; Triticum strigosum Less- 
ing, not Boiss.; Bromus strigosus Bbrst., and to Triticum caninum gmelini Griseb. 
Thurber are out in Brewer and Watson’s Botany of California (2:324), that 
it does not agree with Triticum strigosum, which has the empty glumes much 
longer and short-awned, the whole spikelet larger and more scabrous, and the 
basal leaves shorter than the culm leaves. The Asiatic material in the National 
n. 
Washington and Oregon to Montana, Colorado, and ployee Specimens in the 
National Herbarium from Washington: 1760, 1911, 1912 C. V. Piper, Pullman 
1894; 141 Vasey, 1883, and Cascade Mountains, 1889; 2135, 2136, 2140 Henderson, 
0 à 
Utah: 729 L. F. Ward, East Humboldt — and 1332 rg Wa tson, 1869, 
Black Rock. Idaho: finales; 1874; 481, 559 San se Heller, and Mappe 
Henderson, 1891; 3702 Henderson, eie 
1892; g, 
— tana: o Seribner, bes 330, 326, 472, 474, 559 Shear, pee 2103, 2110 Rydberg, 
lorado: E : 1885. Arizona: J. G. Le 
