140 FESTUCEAE 



66. FESTUCA L. Fescle Grasses. 



Annuals or biennials. 

 Spikelets loosely 1- to 5-, rarely 6 flowered. 1. F. pacifica. 



Spikelets densely 8- to 13-flowered. 2. F. octoflora. 



Perennials. 



Empty glumes thin, ovate-lanceolate, more or 

 less scarious; second glume l-nerved or 3- 

 nerved only at the base; ligules long and ac- 

 uminate. 3. F. thurberi. 

 Empty glumes tirni, the second 3- to 5-nerved. 



Plant low. less than 1 foot high. 4. F. brachyphylla. 



Plants much taller, fully 2 feet high or more. 

 Leaf blades very narrow and filiform, invo- 

 lute, dull gray green. '>. F. arizonica. 



Leaf blades wider and flat (not involute), 

 . bright green. 



Spikelets narrow, 3- to 5-flowered. 6. F. fratercula. 



Spikelets ovate or oblong, 5- to 11- 



flowered. 7. F. elatior. 



1. FestUCa pacifica Piper. A Pacific Coast ojass col- 

 lected but once near Las Vegas. The determination may not be 

 correct as the material was scanty. 



2. FestUCa octoflora Walt. A common North American 

 species occurring in dry soils in the Sonoran Zones. 



3. Festuca thurberi Vasey. A high mountain species oc- 

 curring in the Canadian and Hudsoiiian Zones. 



4. Festuca bracliyphylla Schultes. On the high mountains 

 in the xiorthern part of the State in the Iludsonian and Canadian 

 Zones and into (he Arctic-alpine Zone. 



5. Festuca arizonica Vasey. Arizona fescue. Common 

 in the cooler forests and on open hums in the high mountains: a 

 valuable grass. Tn the Canadian and Iludsonian Zones. '^lOmctimes 

 coming into the Transiticm. 



6. Festuca fratercula Rupr. Also found on the high moun- 

 tain peaks; rare. 



7. Festuca elatior L. Tau, Fescue. lias been introduced 



at various places and escaped at the higher levels in the mountains. 



