MONOCOTYLEDONES. 87 
488. A. PRa&COx (Linn.), Harly Hair-grass. 
Common. 
Genus CCXVII—AVENA (Linn)., Oat-grass. 
489. A. PUBESCENS (Huds.), Downy Oat-grass. 
Scarce. 
Manse of Hoy and Scapa (Dr Boswell); Gills of 
Scapa (Dr Gillies). 
490. A. PRATENSIS (Linn.), Narrow-leaved Oat- 
grass. Doubtful (D. Macnab). 
491. A. stTricosA (Schreb.), Bristle Oat-grass. 
Introduced. 
492. A. FaATUA (Linn.), Wild Oat-grass. Intro- 
duced. 
Genus CCXVIIL—ARRHENATHERUM (Beauv.) 
493. A. AVENACEUM (Beauv.), False Oat-grass. 
Common. 
Var. bulboswm (Presl.) Common. 
The variety is a weed which in impoverished 
lands becomes a very disagreeable pest. In Orkney 
it is named “swine-beads,” probably because pigs 
rutted them up and fed on them. 
Genus CCXIX.—TRISETUM (Pers.), Yellow Oat-grass. 
494, T. PRATENSE (Pers.) Not common. 
Fields ; sandy spots (R. Heddle). 
Genus CCXX.—HOLCUS (Linn.), Soft-grass. 
495. H. MOLLis (Linn.) 
Dr Duguid and R. Heddle say it is common; but 
this is probably a mistake. 
