47 
wettest places, chiefly near the willow margins. As reference to other parts 
of this paper will show, Carex trichocarpa var. aristata is extremely variable 
in its selection of habitats, for it seems to flourish equally well in the broad 
marshes of delta plains, in semi-dried flood-plain sloughs, in water 4 feet 
deep on the shores of marshy lakes, and here in the semi-open prairie where 
it has to compete with a large number of grasses and other herbs. Its 
more common wet shore habitat, however, indicates wetter conditions for the 
whole growing season in the 11-mile area than in the 18-mile area. Occa- 
sional marshy depressions show typical wet meadow 7 plants such as Glyceria 
pulchella arid Rumex Occident alts. 
One of the most striking features of these prairies is in the colour and 
luxuriance of their vegetation. In late June and early July they were turned 
blue by the cowslip Mertensia paniculata. By the latter part of July this 
w r as mostly changed to purple by delphiniums, with dashes of white made 
by the northern bedstraw Galium boreale, and yarrow Achillea Millefolium, 
and of yellow* made by the mustards and by avens Geum strictum and 
G. macrophyllum var. perindsum. Delphinium was growing abundantly 
over 5 feet high, and one record plant measured 9 feet 3 inches with a 
portion of its infloresence still unfolded. Blue-joint grasses, blue-grasses, 
and fireweeds w r ere growing over 5 feet tall, and the cow-parsnip Heracleum 
lanatum was well over 6 feet. 
At the 11-mile area the spruce timber margins the prairie, where it 
seems to be growing in a virgin state. The transition is marked by clumps 
of grey willow's, and an indefinite mingling of prairie and woodland species. 
With the appearance of wroodland mosses there come w T etter conditions than 
occur at poplar margins. Most of the prairie species are present in reduced 
numbers, so the list of secondary species given here will be limited to the 
woodland element in the flora. 
Primary spp.: Scilix Bebbiana 
C alamaqro&tis canadensis var. robusta 
Secondary spp.: Picea glaucu (young saplings) 
Betula papyri fern var. neoalaskana 
Arenaria lateriflora 
Ribas hudsonianum 
Frag aria ylauca 
Rubus pubescens 
R. acaulis 
Lathyrus ochroleucus 
Corrms stolonifera 
Viburnum pauciflorum 
Solidago multiradiata var. scopulorum 
Arnica rhizomala 
Wetter areas 
Carex disperma 
C. vaginata 
Parnassia multiseta 
P. montanensis 
Senecio pauper cuius 
Eng cron acris var. arcuans 
Rosa acicularis and Syrnphoricarpos ocddentalis, listed with the prairie 
flora, show considerable increase in abundance at the wdllow margins. The 
young spruce saplings have long, horizontal roots which rgach through the 
new leaf mould beneath the willows. A tree 5 or 6 feet tall will have one 
91963 — 4 } 
