THE GRASS TRIBE. '261 



their structure that you may well believe there is some 

 little difficulty in distinguishing them into genera ; 

 especially as their parts are so small. Although it is 

 no part of my plan to teach you much of the distinc- 

 tions of genera, that being left you to acquire from 

 systematic works, when the difficulties of this intro- 

 duction are mastered ; yet I may as well explain how 

 a few of the very commonest genera are known from 

 each other. 



What has already been said of the Brome-grass 

 explains its characters. Very nearly related to it are 

 Fescues (Festuca), the species of which, whether high- 

 landers or lowlanders, are so much and advantageously 

 employed as pasture Grasses ; they differ from the 

 Brome-gTasses only in having their beard proceeding 

 from the very point of the palea, instead of from below 

 its point. Like both these are the Meadow-grasses 

 (Poa); but they have no beards at all, and are usually 

 much smaller : the little annual Grass which grows 

 every where, and flowers at all seasons of the year, 

 lying almost prostrate upon the ground, is a kind of 

 Poa (P. annua). Quaking-grasses (Briza) are Poas 

 with their palea? inflated. All the above have a loose 

 inflorescence, and several florets in each spikelet. 



Others, having also a branched inflorescence, are 

 known by each spikelet containing but one floret ; 

 such as Bent-grasses (Agrostis), with thin delicate 

 silken panicles and wiry stems ; they have often only 

 one palea3 instead of two, or if they have two, the 

 upper one is very minute. To Grasses with a similar 

 structure also belong the Feather-grass (Stipa), with 



