1] ANNUALS AND PERENNIALS 4 
which may become biennial or perennial. 
Alopecurus geniculatus. 
Hordeum pratense. 
Lolium perenne. 
L. italicum (may be perennial). 
Bromus asper (may be perennial). 
B. sterilis. 
B. arvensis (may be perennial). 
Holeus lanatus. 
H. mollis. 
Nardus. 
Hordeum sylvaticum. 
Agropyrum. 
Brachypodium. 
Bromus erectus. 
B. giganteus. 
Festuca ovina. 
F. elatior. 
F. sylvatica. 
Dactylis. 
Cynosurus cristatus. 
Briza media. 
Milium. 
Anthoxanthum. 
Digraphis. 
Phleum pratense. 
Alopecurus pratensis. 
Agrostis alba. 
A. canina. 
PERENNIALS. 
Psamma. 
Awa cespitosa. 
A. flexuosa. 
A, canescens. 
Avena pratensis. 
A. flavescens. 
Arrhenatherum. 
Glyceria aquatica. 
G. fluitans. 
Poa maritina. 
P. compressa. 
P. pratensis. 
P. trivialis. 
P. nemoralis. 
P. alpina. 
P. bulbosa. 
Molinia. 
Melica. 
Triodia. 
Keleria. 
Arundo. 
The rhizome of a perennial grass is continued sym- 
podially by means of buds branching from the lowermost 
joints of the flowering shoots, and some importance is 
attached to the mode of spreading of these lateral sprout- 
