Alpine and Arctic Floras 
This will explain what is really the chief difficulty of 
the arctic, and in a less degree of our highland and other 
alpine forms. Being in sunshine they must, of course, 
respond to it and set about the work of assimilation. But 
where is the water to come from? Roots, stems, and 
branches are frozen hard, and no water can reach them. 
So surrounded by leagues of frozen water, these 
wretched plants are actually perishing of thirst. 
The cold itself is by no means so dangerous an evil 
as this, for, as we have seen, seeds when dry can support 
an almost unimaginable number of degrees below zero, 
So arctic plants manage somehow to keep down the 
loss of water by transpiration. They require but very 
small amounts of water even in relatively high tempera- 
tures, as has been shown by actual measurement.” 
Perhaps one should mention here a strange fact that 
has been recently commented on by several botanical 
authorities. In some respects there is a wonderful 
resemblance between all “open” floras wherever they 
may occur. Such apparently different associations as 
these arctic plants, desert plants, others which live above 
the clouds in the dry cold regions of Tibet and the Andes, 
marine plants, not only those of salt marshes but of 
sandy sea-shores, rock “ floors” and the like, often show 
a peculiar and interesting resemblance. 
The explanation seems to lie in the fact that all such 
floras must do with as little water as possible. In the 
deserts and above the clouds, simply because there is 
extremely little to get; in frozen ground it is not avail- 
able, and in salt soil it is of so poisonous a character 
that they reduce their demand for water to a minimum. 
One of the most salient characters of alpine plants is 
the dwarf, stunted character of most of them. One 
need only refer to the tiny willows, a few inches high, 
which represent the genus Salix at great altitudes, 
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