8 ROOTS AND STOLONS [CH. 
Aira canescens (Grey Hair-grass). 
A. precor (Early Hair-grass). 
A. caryophyllea (Silvery Hair-grass). 
Nardus stricta (Moor Mat-grass). 
Hordeum murinum (Wall Barley). 
H. maritimum (Sea Barley). 
Lolium perenne (Rye-grass). 
L. temulentum (Darnel). 
Bromus arvensis (var. mollis). Field Brome. 
Festuca ovina (Sheep’s Fescue). 
F. Myurus (Rat’s-tail Fescue). 
Briza media (Quaking-grass). 
Poa maritima (Sea Poa). 
P. annua (Annual Meadow-grass). 
P. compressa (Flattened Meadow-grass). 
P. alpina (Alpine Poa). 
P. bulbosa (Bulbous Poa). 
Triodia decumbens (Heath-grass). 
Keleria cristata (Crested Keeleria). 
The roots of our grasses are almost always thin and 
fibrous and are adventitious from the nodes, frequently 
forming radiating crowns round the base and easily pulled 
up, and usually broken in the process; but in the case 
of a few moor grasses—especially Nardus (Fig. 2) and 
Molinia—the roots are so tough and thick (stringy) as to 
resist breakage very efficiently. In stoloniferous grasses a 
similar difficulty of removal may be caused in a slighter 
degree by the underground stems. In a few cases, e.g. 
Alopecurus bulbosus (Fig. 3), Poa bulbosa, Phlewm pratense 
and P. Behmeri, Arrhenatherum avenaceum, and to a 
slighter extent in Poa alpina and one or two others, the 
lowermost internodes and sheaths of the stems may be 
swollen and stored with food-materials, and a sort of tuber 
or bulb results; this is especially apt to occur in dry sandy 
