174 THE FOREST LANDS OF NORTHERN RUSSIA. 
intense warmth,—consisting of potentillas, gentians, starry 
chickweeds, spreading saxifrages and sedums, spireas, 
drabas, artemisias, and the like. The power of the sun is 
so great, and the consequent rapidity of growth so extra- 
ordinary, that these plants spring up, and blossom, and 
germinate, and perish, in six weeks. In a lower latitude 
many ligneous plants are found,—as berry-bearing shrubs, 
the glaucous kalmia, the trailing azalea, the full-blossomed 
rhododendron, The Siberian flora differs from the Euro- 
pean in the same latitudes by the inclusion of the North 
American genera, phlox, mitella, and claytonia, and by the 
luxuriance of its asters, spireas, milk-vetches, and the 
saline plants goosefoot and saltwort. 
‘In Nova Zembla, and other northern regions, the vege- 
tation is so stunted that it barely covers the ground, buta 
much greater variety of minute plants of considerable 
beauty are aggregated there in a limited space than in the 
Alpine climes of Europe where the same genera occur. 
This is due to the feebleness of the vegetation; for in the 
Swiss Alps the same plant frequently usurps a large area, 
and drives out every other,—as the dark-blue gentian, the 
violet-tinted pansy, and the yellow and pink stone-crops, 
But in the far north, where vitality is weak and the seeds 
do not ripen, thirty different species, it has been observed, 
may be seen “crowded together in a brilliant mass,” no 
one being powerful enough to overcome its companions, 
In these frozen climates plants may be said to live between 
the air and the earth, for they scarcely raise their heads 
above the soil, and their roots, unable to penetrate it, creep 
along the surface. All the woody plants—as the betula 
nava, the reticulated willow, andromeda tetragona, with a 
few bacciferous shrubs—trail upon the ground, and never 
rise more than an inch or two above it. The Salix lanata, 
the giant of the Arctic forests, is about five inches in 
height ; while its stem, ten or twelve feet long, lies hidden 
among the moss, and owes shelter, almost life, to its humble 
neighbour. 
‘In the wooded zone the thermometer does not rise 
