122 GRASSES OF SCOTLAND. 



found in open situations. It is a tall coarse grass, not recommended 

 for agricultural purposes. Horses and cows eat it in common with 

 other grasses of the wood, but they give a preference to pasture grass, 

 except in cases of necessity when quantity is of greater consideration 

 than quality. It is a common grass in Scotland, England, and Ire- 

 land ; also a native of Norway, Sweden, Germany, Switzerland, 

 France, Italy, and Russia. Not found in America. Its limit of 

 altitude is about 500 feet above the sea. 



Flowers in the third week of July, and ripens its seed about the 

 end of August. 



81. Trisetum pratense.* 

 Narrow-Leaved Oat- Grass. 



Specific Character. — ^Leaves and sheaths not hairy. (Plate LII.) 

 Description. — It grows from eighteen inches to two feet high. The 

 root is perennial, fibrous. Stem erect, nearly round, smooth, and 

 finely striated, bearing from three to four leaves with striated sheaths ; 

 the upper sheath very long, more than thrice the length of its leaf, 

 slightly roughish to the touch, crowned with a long narrow sharp 

 membranous ligule ; lower sheaths much shorter than their leaves, 

 and generally smooth. Joints three, smooth, situated near the base. 

 Leaves, in exposed situations narrow, linear, acute, generally folded, 

 harsh, smooth on the back, and rough on the inner surface. On each 

 side of the central rib are two light-green lines, very perceptibly seen 

 when the leaf is held against the light. Inflorescence compound ra- 

 cemed or simple panicled ; the first three or four spikelets arising im- 

 mediately from the rachis on short footstalks, the lower spikelets 

 mostly in pairs on long peduncles. Panicle long, erect, close, the 

 rachis and branches rough. Spikelets large, of an oval form, of four 

 or five awned florets scarcely protruding beyond the calyx. Calyx 

 of two unequal acute glumes (Fig. 1), roughish at the keel, three- 

 ribbed, purplish on the lower half. Floret of two paleae, (Fig. 2), 

 the outer palea of lowermost floret acute, often bifid ; membranous 

 on the upper part ; roughish on the keel ; five-ribbed ; hairy at the 

 base. Liner palea about one-fourth shorter than the outer palea, flat, 



* Arena pratense, Koch, Smith, Hooker. 



