CL. III.] 



5. POA TRIVIALIS. 



351 



of three glumes, the valves of which are observed to have 

 five fine nerves ; on the margin they are of a reddish colour, 

 and at the base they are united by tufts of hair, (94.) 



The g-eneric character of the Poa is constituted by the 

 oval shape of the ear, and by the valves being destitute of 

 awns. 



The species most nearly related to this are the P, praten' 

 sis, serotina Ehrh. and nemoralis. The former is distin- 

 guished by its creeping root, its smooth stem, its short, 

 truncated, and unprojecting ligula, and by its earlier season 

 of flowering. For it is in full flower in May, whilst the Poa 

 trivialis begins to blossom in June. 



The Poa serotina Ehrh., is distinguished from our grass 

 by a root slightly creeping ; by a ligula, which projects but a 

 little, and which is truncated ; by a panicle of a more pyra- 

 midal shape, having its subordinate stalks open, but not re- 

 flex ; by its ear being smaller and more of a spear-shape, its 

 glumes being commonly five, and coloured yellow at the 

 point. This species also blossoms later than the P. trivialis. 



The Poa nemoralis is distinguished by a stalk as smooth 

 as that of the P. trivialis, being, at the same time, a little 

 compressed. The ligula is also truncated. The panicle is 

 not uniformly spreading, but tapering, and inclining towards 

 one side. The ears are lanceolate, contain commonly three 

 glumes, which are open, and have long projecting points. 

 At their base, too, they are almost completely free, althougk 

 some small hairs appear here also. 



Geographical Distribution. 



The Poa trivialis is one of the plants which have the most 

 extensive distribution in Europe. Towards the north it ex- 

 tends beyond the polar circle, and constitutes the principal 

 produce of the meadows in Lapland. It is also very com- 

 mon in Northern Asia, and in North America. Towards 

 the south it constitutes the chief riches of the meadows in Pe- 

 loponnesus. All the countries of Europe, Asia, and Ame- 

 rica, which lie between the 36^ and 68" N. Lat., furnish. 



