THE RETICULATE WILLOW 187 



The High Alpine Willows. 



We are accustomed to think of the Willows 

 (natural order Salicacese) as being good-sized trees, 

 as with us in England. Even in the Alps the Willows 

 manage to hold their own, owing to their marvellous 

 power of adapting themselves to a set of physical con- 

 ditions, entirely different from those met with in the 

 plains. As they ascend the Alps, they discard the 

 tree habit. They gradually become reduced to dwarf 

 shrubs, and then finally in the High Alpine regions 

 to carpet plants, which are only slightly woody. The 

 gradual dwarfing of a tree-form, as the altitude 

 increases, is well seen in other plants, such as the 

 Juniper and the Mountain Pine, which will be dis- 

 cussed in a later chapter, but nowhere is it found 

 perfected to the degree met with in the High Alpine 

 Willows. 



The carpet-forming Willows do not belong to the 

 same species as those found in the plains, nor are 

 they regarded as varieties of Lowland species, as is 

 the case with Juniperus communis, var. nana, Willd. 

 There are two Carpet Willows confined to the High 

 Alpine region, which we will now compare. 



The Reticulate Willow. 



The Eeticulate Willow {Salix reticulata, Linn.) 

 (Plate XXX VIL) is the best known and the 

 handsomest of the Alpine Willows. It is usually 

 very abundant on old or new moraines of glaciers, 



