PLANTS OF THE MOORLAND 93 



plants should be evergreens. Would it not be better 

 to reduce the loss of water to a minimum by shedding 

 the leaves in autumn? The answer given by Pro- 

 fessor Schimper in his "Plant Geography" (Oxford, 

 1903) is that the evergreen habit is not suited to 

 heath or moorland conditions; it is a legacy dating 

 from other and more hospitable surroundings. It is 

 a hereditary characteristic of the Heath family (Erica- 

 ceae), which is retained under the most diverse 

 climatic conditions. We should also notice that the 

 leaves of many evergreens are leathery, which also 

 lessens the loss of water, and reduces the risk of being 

 evergreens in conditions where this is not a profitable 

 habit. 



Also characteristic of heaths are three nearly related 

 plants, different kinds or species of Vaccinium. The 

 first is the Blaeberry, Billberry, or Whortleberry (Vac- 

 cinium myrtillus), with the young leaves a beautiful 

 rose colour, hinting at the rosy-greenish flower. The 

 leaves fall off when cold weather sets in, unless it be 

 in very sheltered places; but the young shoots are 

 green and probably do some leaf-work (photo-syn- 

 thesis) in the winter sunshine. Everyone knows the 

 delicious flavour of the dark blue fruit. The Blae- 

 berry often forms a thick carpet in Pine forests, and 

 this familiar fact may be taken as giving us a useful 

 hint that some of our heaths have grown up in place 

 of forests that have been cleared away. 



The second kind (Vaccinium uliginosum) has a pale 

 pink flower and a berry smaller than that of the Blae- 

 berry, but of the same colour. It ascends to 3,500 feet 

 in the Scottish Highlands. The third kind is the 

 Cowberry (Vaccinium vitis-id&a), with leaves like those 



