4 GRASSES OF SCOTLAND. 



about half the length of the floret. Leaves broad. Ligule prominent. 

 Two species. (Plate IX.) 



16. HORDEUM. — Inflorescence racemed, dense, bristly. Spike- 

 lets in threes, arranged alternately on the toothed rachis. Glumes 

 terminating in long, rough, bristly awns. Three species. (Plates 

 X. XI.) 



19. POLYPOGON. — Inflorescence panicled, dense. Glumes of 

 equal lengths, linear, hairy, with long awns. Floret about half the 

 length of the glumes, with a short terminal awn. One species. (Plate 



XL) 



20. AGROSTIS. — Inflorescence panicled, spreading. Glumes 

 nearly of equal lengths, acute, not awned ; outer glume the larger. 

 Floret much shorter than the calyx, of two very unequal palese, some- 

 times the inner palea is wanting ; occasionally the base is furnished with 

 a minute tuft of hairs. Three species. (Plates XII. XIII. XIV. 

 XV.) 



23. CAL AM AGROSTIS. — Inflorescence panicled, spreading. 

 Glumes of about equal lengths, not awned. Outer glume the smaller. 

 Floret of two very unequal palese ; outer palea awned, furnished at 

 the base with long straight hairs, more than half the length of the flo- 

 ret, sometimes longer than the floret. Two species. (Plate 

 XVL) 



25. ANEM AGROSTIS. — Inflorescence panicled, spreading. 

 Glumes unequal, the outer glume the smaller. Floret as long as the 

 calyx. Outer palea with a long dorsal awn more than thrice the 

 length of the palea. One species. (Plate XVII.) 



26. IMILIUM. — Inflorescence panicled, spreading, loose. Glumes 

 nearly equal, somewhat hairy, smooth on the keels, three-ribbed. Flo- 

 ret nearly as long as the calyx, smooth, not awned, without lateral 

 ribs. Leaves broad and flat. One species. (Plate XVIL) 



