83 
Where the water is nearly or quite evaporated off during the summer, 
leaving a semi-dry condition for a short period, Bidens ceases to make a 
consistent zone, and is broken up by alternating Typha latifolia, Carex 
rostrata, and Glyceria grandis. The cat-tail Typha is variable in its selec- 
tion of a habitat, sometimes appearing at the edge of standing water where 
it alternates with Bidens, and in others showing its ability to withstand 
desiccation better than the latter species by growing in semi-dry muck. 
Sloughs in a nearly dry state, like those at the Hay Camp, have an open 
association, on exposed damp ground, of Beckmannia Syzigachne , Alopecurus 
aequalis, Eleocharis aciculans , and Rumex maritimus var. fueginus. Sev- 
eral random observations here and in the Murdock Creek meadows indicate 
that Beckmannia finally dominates this group and is possibly the last stage 
prior to the complete dominance of the meadow vegetation by Carex tricho - 
carpa var. anstata. There are small patches of Beckmannia in nearly pure 
stand surrounded completely by the sedge. 
The second zone of shore plants is made up almost exclusively of Carex 
rostrata, which usually follows the emergent aquatics already described. 
It has only a few associates, mainly the more water-loving plants of the 
meadow flora, and merges imperceptibly into the Carex trichocarpa asso- 
ciation. 
MEADOW ASSOCIATIONS 
In general aspect the wet meadow association of the tall sedge Carex 
trichocarpa var. aristata closely resembles that of the delta plains. It is 
drier here, however, and contains a number of secondary species not 
observed in the lower areas. 
Primary sp.; Carex trichocarpa var. aristata 
Secondary spp.: Fluminia festucacea 
C alamagrostis inexpansa var. brevior 
Agrostis scabra 
Polygonum natans forma Hartwrightii 
Rumex occidentalis 
Stellaria longifolia 
S. borealis 
Rorippa palustris 
Geum macrophyllum var. perincisum 
Potentilla norvegica var. hirsuta 
Epilobium palustre 
Sium suave 
Mentha canadensis var. glabrata 
Stachys scopulorum 
Scutellaria epilobiifolia 
Galium trifidum 
Aster puniceus 
A. junceus 
Cirsium Drummondii 
The dominant Carex is rarely found in fruit in these meadows. The 
writer has collected the species in deep water on the shore of Moose lake 
where it was fruiting heavily in August, 1929. It was also fruiting in the 
wet meadows about lake Mamawi and in the semi-open prairies at the base 
of the Caribou mountains in 1930. During its fruiting season in 1928 it 
was necessary to make a long search in the meadows at the Hay Camp 
and at Murdock creek to find enough fruit for specimens. In these meadows 
