FLOWERING PLANTS AND FERNS OF ARIZONA 87 



20. Bromus trinii Desv. in Gay, Fl. Cliil. 6: 441. 1853. 



Mohave, Maricopa, and Pinal Counties, dry plains and wooded 

 slopes, March to May. Oregon and Colorado to Arizona and Baja 

 California ; introduced from Europe. 



2. FESTUCA. Fescue 



Plants annual or perennial; spikelets in narrow or open panicles, 

 few- to several- (rarely 1-) flowered; raehilla disarticulating above 

 the glumes and between the florets; glumes narrow, acute unequal; 

 lemmas rounded on the back, 5-nerved, usually awned from the tip 

 or rarely from a minutely bifid apex. 



Although inclined to become rather tough with age. the fescues are 

 browsed extensively by sheep in the high mountain parks, where 

 Arizona fescue (F. arizonica) is particularly abundant. The small 

 annual sixweeks fescue (F. oetoflora) furnishes winter and spring 

 forage in Arizona. Sheep fescue (F. mind) and red fescue (F. rubra I 

 are cultivated to a limited extent in the eastern United States in lawns 

 and pastures. Meadow fescue (F. elatior) is cultivated for hay and 

 pasture in the central United States. 



Key to the spec it s 



1. Plants annual: Section Yulpia (2). 



2. Spikelets more than 5-flowered, the florets crowded: lemmas 4 to 5 mm. 

 long, the margins inrolled: awns 2 to 5 nun. long. 1. F. octoflora. 

 2. Spikelets usually fewer than o-flowered or, if more than 5-flowered, then the 

 lemmas 7 to 8 mm. long, and the awns 10 to 13 mm. long (3). 

 3. Lemmas ciliate toward apex; first glume usually minute. 



2. F. MEGALURA. 



3. Lemmas not ciliate: first glume more than half as long as the second (4). 

 4. Spikelets glabrous (5). 



5. Pedicels appressed: spikelets mostly 3- to 5-flowered. 



3. F. PACIFICA. 



5. Pedicels spreading, especially those on the upper part of the main 



axis: spikelets 1- to 2-flowered 4. F. reflexa. 



4. Spikelets pubescent (6). 



6. Pedicels appressed; lower branches of the panicle spreading or re- 



flexed; lemmas hirsute; glumes glabrous or pubescent. 



5. F. GRAYI. 



6. Pedicels and panicle branches finally spreading or reflexed: glumes 



and lemmas pubescent 6. F. ea^twoodac 



1. Plants perennial: Section Eufestuca (7). 



7. Leaf blades flat, 3 to 6 mm. wide, rather thin; lemmas acuminate, sometimes 

 with an awn as much as 2 mm. long (8). 

 8. Spikelets mostly not more than 5-flowered 7. F. sororia. 



8. Spikelets mostly 8- to 10-flowered 8. F. elatior. 



7. Leaf blades involute, les< than 3 mm. wide (9). 



9. Ligule 2 to 4 mm. long or longer 9. F. thurberi. 



9. Ligule short (10). 



10. Culms loosely tufted, decumbent at base: lower sheaths red, fibrillose; 



blades soft, glabrous _ 10. F. rubra. 



10. Culms densely tufted: blades hard and firm, usually scalm>u< (11). 

 11. Panicle narrow, the brandies appressed: lemmas 4 to 5 nun. long; 

 blades short .__ .11. F. oviw. 



11. Panicle open, the branches ascending or spreading; lemmas about 7 

 mm. long: blades elongate (12). 



12. Awns 2 to 4 mm. long 12. F. idahoensis. 



12. Awns verv short or obsolete 13. F. arizonica. 



