THE NATURAL HISTORY OF BRITISH GRASSES. 13 
Docks, too, such as Rumex crispus (curled dock), and 
Rumex pratensis (meadow dock), often greatly increase by 
irrigation; these, however, are soon destroyed, and if not 
allowed to seed give but little trouble. 
5. Agrarian Grasses are more properly those which occur 
in land under tillage ; they are not a large list, nevertheless 
they will be found worthy careful study, as all of them are 
weeds and many of them great pests. Some, as the couch 
grasses, are troublesome, for their creeping underground 
stems as well as growth of herbage. The wild oat occupies 
the ground with a larger plant than the cereal with which 
it usually grows, whilst others are sure indicators of a low 
state of fertility, and often of bad farming. The following 
is a list of the Agrarian Grasses :— 
Avena fatua—Wild oat. 
45 strigosa—Bristle-pointed oat. 
Alopecurus agrestis—Slender foxtail-grass. 
Bromus mollis—Soft brome-grass. 
$5 secalinus—Smooth rye brome-grass. 
35 sterilis—Barren brome-grass. 
Lolium tremulentwn—Bearded darnel. 
Poa trivialis—Roughish meadow-grass. 
» annua—Annual meadow-grass. 
» compressa—Flat-stemmed creeping meadow-grass. 
Triticum repens—Couch-grass. 
Agrostis stolonifera—Creeping bent-grass. 
Of these, the most mischievous—for all are weeds in 
arable—are the couch tribe. These the farmer knows well 
how to cope with, and as this is the case, it is somewhat 
surprising that there is so much couch to be got rid of 
everywhere; this too often arises from the work being 
behind-hand, in which case the seed has often to be sown 
before the land is clean, and with couch a blade left here 
and there is quite sufficient to spread over a field in a 
short time. 
In the Cotteswold district, where all three of the creep- 
ing grasses are in abundance, a distinction is made in them 
