Sy ee Le ee ee ee 
gab 
RYDBERG: PHYTOGEOGRAPHICAL NOTES 473 
*Betula glandulosa Phyllodoce glanduliflora 
*Alnus sinuata Kalmia microphylla 
Phyllodoce empetriformis *Ledum glandulosum 
In the Canadian Rockies are added to these: 
Salix alexensis Salix Barattiana 
Salix arbusculoides Salix Drummondiana 
7. SNOW DRIFT FORMATION 
This special formation is made up of hydrophytic plants, 
nearly all of the family Ranunculaceae. The other plants are 
such as are only occasionally found in these peculiar situations. 
This formation could be included in the alpine seeps on account 
of their moisture, but the ground is neither rocky nor does it con- 
tain much humus. As a rule the soil is considerably clayey. In 
reality it is a part of the alpine meadow, modified by the slowly 
melting snowdrifts. The formation is found only in hollows or on 
gentle slopes, where large snowdrifts have lodged during the winter 
and the ground does not become bare before late in the summer. 
The grasses and most other meadow or bog plants could not with- 
stand such severe conditions. Where the snowdrifts have been the 
ground is perfectly bare or nearly so, except for these peculiar 
plants, which appear as soon as the snow has melted and the 
ground has had time to thaw a few inches deep. Sometimes they 
even come up through the snow. Hence, the stories of the snow 
plants often heard of are not altogether “ fakes.” 
This formation is principally made up of the following plants: 
Southern Northern 
Ranunculus adoneus Ranunculus eximits 
Ranunculus alismaefolius Ranunculus alismaefolius 
Ranunculus stenolobus Caltha leptosepala 
Caltha rotundifolia Caltha Cheledonti 
8. ALPINE LAKES 
The aquatic flora of the alpine region is rather meagre. All 
the phanerogams and fernworts found there are found also in the 
subarctic region, in fact, are boreal plants of wide distribution. 
The flora of the alpine lakes is limited to the following phanero- 
sams and fernworts: 
