oh, vii] Botanical Description of Species 



127 



cylindrical, rough or pubescent (a microscopic feature). A well- 

 developed "web" is present in "uncleaned" samples. Seen in 

 bulk the "seed" has a paler appearance than that of P. pratensis 

 or P. trivialis. 



Poa pratensis, L. (Smooth-stalked Meadow-grass.) (Figs. 5 and 

 141.) See p. 159. 



A common species throughout the British Isles in pastures, 

 meadows, and on road-sides. It is a perennial, and creeps exten- 

 sively by extravaginal rhizomes. Young shoots flattened, with 



Kg. 142. "Seed" of Poa pratensis. x 10. 

 To the right is shown the appearance of 

 the hair fringe on the margins of the 

 inner palea when highly magnified. (Com- 

 pare with Poa compressa, Fig. 138.) 



Fjg.143. "Seed" 

 of Poa trivialis. 

 x 10. 



rounded-off keels. Sheaths entire. Blade dark-green, conclupli- 

 cate, short or long, with almost parallel margins suddenly 

 narrowing and curving upwards to an abrupt blunt point; ribless 

 above, distinctly keeled below. The flanking lines of motor cells 

 can usually be readily seen, one on each side of the mid-rib. 

 Ligule short and blunt, sometimes almost obsolete. No auricles. 

 The whole plant glabrous. 



There are several distinct forms of this species differing much 

 in regard to the width and stiffness of the blades. The above 

 description applies to the form most frequently met with (var. 



