FESTUCE.E. 527 



the floral glume often adheres more or less, whilst there are several 

 true Festucas where it is quite free. 



Most of the species widely dispersed are very variable aud diffi- 

 cult to define. Beutham proi^oses no sections for the genus, but 

 refers to some proposed by C. Koch : 



1. Pseudopoa, spikelets very small and with nearly the habit of 

 Nephelochloa. 



2. Leucojma Griseb., S2:)ikelets rather larger than usual, and 

 with glumes somewhat scarious aud shining. 



3. Dioicopoa Desv., spikelets usually, iiossibly not always, dioe- 

 cious. As will be seen, I have made a jmrely artificial key for our 

 -species of Poa. 



A. First empty glume 1-nerved, annuals (a) 



a. Ligule 2-3 mm. long, spikelets 3-7-flowered, floral 



glume 2-3 mm. long 1 



a. Ligule 2 mm. long, spikelets 2-4-flowered, floral glume 

 3 mm. long 2 



B. First empty glume 1-nerved, perennials (a') 



a'. Upper ligule 5-6 mm. long, rays in sets of 5-6, floral 



glume 2.5-3 mm. long 3 



a'. Upper ligule 5 mm. long, fays 3— t, floral glume 



5.5-6.5 mm. long 4 



a'. Upper ligule 4 mm. or less in length (b) 



b. Floral glume 6 mm. long; both empty glumes 1- 



nerved 5 



b. Floral glume 4.2-5 mm. long, ligule 2-3 mm. long 6 

 b. Floral glume less than 5 uim. long, except some 



of no. 16 (c) 



c. Ligule 0.7 mm. long, rays in twos, floral glume 



2.7-3.2 mm. long 7 



c. Ligule 1 nmi. long, rays 2-4, floral glume 4 



mm. long, upper leaf 1.5 cm. long 8 



c. Ligule 1 mm, long, rays 3-5, floral glume 3,5-4 



mm. long 9 



0. Ligule 1-2 mm. long, floral glume 3-4,5 mm. 

 Ions: 10 



