n GRAMINE^ 443 



down as in so many other grasses. The flowers open, 

 according to Kerner, between 6 and 7 a.m., according 

 to Warnstorf, between 6 and 9. 



Cy^s-ostjrus (Dog's-tail) 



C. cristatus. — A slender species with almost filiform 

 leaves. The flowers are homogamous, ^Yith anthers 

 yellow or violet. 



Briza (Quaking Grass) 



B. media. — The flowers are homogamous, and open 

 once in the morning and once in the evening between 

 6 and 7. The glumes are large, concave, and serve 

 as a wing to the small fruit. 



PoA (Meadow Grass) 



P. pratensis. — A common meadow grass. The 

 flowers are homogamous ; the anthers open about 

 mid-day. 



P. annua. — Though annual Avith us, this species is 

 said to be perennial on the summits of the Pyrenees.^ 

 Similarly in the Flora of British India, where it appears 

 as an alpine on the hills of Northern and Southern 

 India, it is described as annual or perennial. In the 

 Swiss Floras it is given as an annual. This is the 

 commonest grass in our parks and by our roadsides. 



P. alpina. — This species is often viviparous, the 

 spikelets being converted into buds. The association 

 of the viviparous condition generally with an alpine or 

 arctic habit is a point of interest. 



Melica 



Our two species of this genus, M. nutans and 

 M. uniflora, occur in woods. The spikelets are two- 

 flowered ; in M. nutans both flowers are hermaphrodite, 

 while in M. unijlora the upper is male. 



^ See Cardamine hirsuta, p. 79, and Constantin, Les vigMaux et Us milieux 

 cosmiques, p. 30. 



