55 
The presence of Rosa , Symphoricarpos, and Populus indicates the trend 
toward mesophytism. The prairies here as elsewhere on the upland seem 
to be encroached upon by the surrounding bush and timber. The floristic 
similarity of these areas to the Peace Point prairie and to the vegetation of 
the dry creeks at the base of Caribou mountains is at once striking. 
The most characteristic feature of the Salt Plains is the salt marsh 
vegetation that inhabits undrained depressions. When the snow melts in 
the spring these depressions nearly all contain shallow pools of water that 
are all dried up by the last of August (9). The result of the temporary 
marsh conditions is a complex zonation of plants around the centres of the 
pools. Gradual evaporation of the water concentrates the salt in such a 
way that the most saline conditions are to be found in the centres which, 
if the pools are large enough, are quite barren of vegetation. Naturally, 
the largest of these barren areas are to be found near the salt springs from 
which the outwash comes. Between the Mission Farm and Salt mountain, 
near the largest of the brine springs, are hundreds of acres of flats devoid 
of vegetation. Small prairie spaces only a few feet above the last- 
mentioned flats have no trace of the halophytic flora, and have timber ad- 
vancing into them. The dried surfaces of the flats are much cracked and 
many have a thin layer peeling off. 
A typical section of the marginal vegetation is given in Figure 7. The 
widths of the associations are variable, of course, with the slopes of the 
depressions. At the edge of the barren space is a rich growth of glasswort 
S alicomia europaea, which is bright red in colour, shading to bluish green 
at the drier edge of its zone. Associated with it are Puccinellia Nuttalliana , 
Suaeda depressa, Spergularia salina, and Plantago oliganthos. Puccinellia 
Nuttalliana grows in tufts and becomes the primary species in the next asso- 
ciation, which is a rather narrow one all around the depression. The species 
in the Salicornia association persist and are joined by Glaux maritima , 
Triglochin maritimum, Chenopodium rubrum, and Distichlis stricta. The 
last becomes primary in places. Along the muddy margins of salt streams 
and around brine springs the flora is largely made up of Triglochin mari- 
timum , Salicornia europaea, and Glaux maritima. 
One of the more prominent associations, in the late summer, is just 
outside that of Puccinellia , and is dominated by wild barley Hordeum 
jubatum. It is easily distinguished at a distance by the reddish to straw- 
coloured, waving heads of the grass. The zone seems to indicate a change 
toward non-saline conditions, wherein some of the halophytic types dis- 
appear and several distinct mesophytes come in. Secondary species are 
Triglochin maritimum, Calamagrostis inexpansa var. brevior, Deschampsia 
caespitosa var. glauca, Atriplex patula and var. hastata, Glaux maritima, 
Aster paudjlorus , and A. ericoides. 
By far the largest herbaceous areas are covered by a close turf made of 
the baltic rush Juncus balticus, and blue-joint grass Calamagrostis inex- 
pansa var. brevior. Neither of these species was found to be fruiting 
extensively. Like the sedges of many of the flood-plain sloughs they seem 
to depend very largely upon vegetative means of propagation. The 
Juncus is known locally as wire-grass, and is not much eaten by stock. 
In a few places Plantago eiiopoda takes a primary position in the list. 
