84 
the plants have interwoven, more or less decumbent stolons or off-sets 
which produce the current year’s growth at their tips. A green bud persists 
through the winter among the dead leaf-bases at the tip of the stolon, and 
appears to be an important item in the winter feed of herds of buffalo 
which have for a long time frequented the sloughs at that season. It is 
possible that continued yearly “ pruning ” of these plants has induced a 
nearly total reliance upon vegetative means of propagation. The sedge 
makes up the bulk of the hay cut at the Government Hay Camp and at 
Ryan’s Hay Camp on the east side of Slave river just above Demicharge 
rapids. 
The Calamagrostis association so prominent on the delta plains is here 
confined to the willow margins of the sloughs where it is associated with 
other herbaceous species similar to those listed for such places in the deltas. 
SHRUB AND TREK ASSOCIATIONS 
The configuration of the willow thickets around the sloughs is shown 
on Figures 13, 14. The transition through these to timber need not be 
discussed further since it differs very little from that in the deltas. Populus 
tremuloides and Betula papyrifera are rather common on the higher ridges 
separating the sloughs, indicating a somewhat more mesophytic trend in 
the successions than appears in the newer flood-plains. 
The contrast between the shrub successions on sandy river flood-plains 
and on slough margins is clearly indicated by the willows in the 30th base 
line district. The following is a table of the species in the order of suc- 
cession: 
SLOUGH MARGINS 
Salix planijolia 
S. petio laris 
S. Bebbiana 
ISLAND FLOOD-PLAIN 
Salix interior var. pedieellata 
S. lasiandra 
S. lutea 
S. Bebbiana 
It will be noted that the two situations have no species in common except 
in the later stages. 
At the western margin of the Hay Camp lowland, small streams flow 
from the Salt Plain to the westward and contribute a little water to the 
narrow sloughs. A section of one of these sloughs (Figure 12, K) shows 
the effect of the slightly saline condition. The centre is nearly dry and has 
a close growth of Beckmannia Syzigachne and Glyceria grandis, but instead 
of being followed by a zone of Car ex rostrata as would be expected, there 
is one of Triglochin maritimum, a characteristic plant of saline slough 
margins in the upland. 
Primary sp.: Triglochin maritimum 
Secondary spp.: Hordeum jubatum 
Beckmannia Syzigachne 
A triplex pat ula 
Ranunculus Cymbalaria 
R. Macounii 
Potentilla Anserina 
Hippuris vulgaris 
Sium suave 
Mentha canadensis var. glabrata 
. Plantago major var. asiatica 
