272 



BRITISH GRASSES. 



says that in America it is called Blue-grass, from its 

 glaucous tint. The webbing of the florets is variable, 



Sir J. E. Smith mentions 

 it as a permanent feature, 

 whilst in the species poly- 

 noda of Dr. Parnell, the 

 webbing is most frequently 

 absent. Yet the other cha- 

 racteristics of the plants are 

 identical. 



Dr. Parnell describes an- 

 other grass, which he calls 

 Poa subcompressa, which 

 only varies from this in the 

 presence of two extra ribs in 

 the outer glumes ; this pecu- 

 liarity is not touched upon 

 by other authors, or it would 

 be accounted at any rate a 

 variety. It is found in the neighbourhood of Edinburgh 

 on the earthy tops of the dykes, and about Aix-la-Cha- 

 pelle, Coblentz, Uatisbon, and Vienna. It grows to a 

 less size than the true P. compressa. 



Dr. ParnelPs P. polynoda is so called because of its 

 numerous joints, which are as many as those of the true 

 compressa. His plant contains a large quantity of sili- 

 ceous matter in its sheaths and stem, which he recom- 

 mends to turners as a substitute for sand-paper in polish- 

 ing wood. This peculiarity can be perceived without a 

 lens, by drawing the stem through the teeth. On ac- 

 count of the presence of the flint particles, no cattle care 

 to eat the grass. 



It flowers in June, and seeds in July. 



