112 



Tribe XL— FESTUCE^. 



Spikelets 2-to many-flowered, usually hermaphrodite, pedicel- 

 late in racemes or panicles, the latter sometimes dense and spike- 

 like; flowering glumes usually longer than the empty ones, 

 awnless or with one to several straight (rarely bent) awns which 

 are either terminal or borne just below the apex. 



This is the largest tribe in the order, numbering 

 76 genera and about 725 species. It contains the most 

 important meadow grasses of the temperate regions as 

 well as the more prevalent grasses of the higher moun- 

 tains within the tropics. The genus Poa, which in- 

 cludes Kentucky blue grass, Texas blue grass, etc., 

 numbers 100 species, and an equal number of species 

 are included in the genus JEragrostis. The Fescues 

 number 80 species, and the tribe takes its name from 

 this genus — Festuca. Orchard grass, Dactylis glome- 

 rata, is a well-known example of this tribe. 



KEY TO THE GENERA OF THE FESTUCE.E. 



1. Flowering glumes with 9-23 awn-like divisions, or awned 

 lobes 2 



1. Flowering glumes with fewer lobes, or entire. 3 



2. Panicle narrow and spike-like ; divisions of the flowering glumes 



awn-like and plumose 86. Pappophorum 



2. Panicle expanded; divisions of the flowering glumes membra- 



naceous, awn-pointed 87. Cottea 



3. Spikelets unisexual, the two sexes very unlike; glumes of the 



pistillate flowers 3-awned, those of the staminate flowers 

 awnless 89. Scleropogon 



3. Spikelets hermaphrodite, or if unisexual, those of the two 



sexes similar 4 



4. Spikelets in groups of three along a common axis, the groups 



readily deciduous as a whole; flowering glumes four-parted, 

 awned between the divisions 88. Cathestecum 



4. Spikelets not in deciduous groups or fascicles 5 



5. Spikelets of two kinds in the same inflorescence, hermaphro- 



dite and sterile 6 



5. Spikelets all alike in the same inflorescence 7 



