3 68 
W. West and G. S. West . 
Veronica alpina, blue both in the flowering and fruiting con¬ 
ditions, is frequent, and in the damper places near trickles of water 
the yellow flowers of Draba alpina are obvious even at a distance. 
Pedicularis QZderi does not extend above 4,700 feet, and P. lapponica 
scarcely enters this zone at all. Arabis alpina can be observed up 
to 5,100 feet, and stunted varieties of Taraxacum officinale extend 
along with Carex rigida to fully 5,000 feet. Ranunculus nivalis 
begins at 4,900 feet near the head of the valley, but further down 
near the “ Vaarstien ” it makes its appearance at just over 4,000 feet. 
Ranunculus glacialis 
first appears at about 
4,800 feet. No alpine 
plant has a more charac¬ 
teristic habitat, occurring 
as it does on the loose 
gray debris of ice-slides, 
snow-slides, and glaciers. 
On the mountains at the 
head of the Driva valley 
it occurs in suitable places 
in great quantity, and 
owing to its exposed 
situation is subject to a 
continuous wind-action. 1 
Where this plant grows 
the ground contains much 
fine detritus and is always 
more or less saturated 
with water, and this fact 
probably accounts for the 
leaf-structure, in which 
the stomata are for the 
most part on the upper 
surface. The palisade is 
three layers in thickness, and under each stoma is a large respira¬ 
tory chamber in the upper layer. The spongy mesophyll possesses 
extraordinarily large intercellular spaces. 
Special comment is necessary on the occurrence of Sednm 
i During four weeks in the month of August, with many fine 
sunny days, it was not possible owing to the wind to obtain a 
photograph of the magnificent clusters of flowers of Ranunculus 
glacialis which occurred so profusely at the higher altitudes. 
Fig. 29. Transverse sections of leaves of 
Sedum Rhodiola from an altitude of 4,900 feet. 
A, in very dry situation ; B, from wet place. 
Sections under same magnification. 
