1905-1906.] Scottish Mountain Plants. 255 



branched bushes that are noticeable from a distance, owing to 

 the light-green of the woolly foliage. S. arbuscula and S. 

 Myrsinites are other characteristic mountain Willows. Three 

 genera which, so far as the Lowlands are concerned, are plants 

 of considerable size, are represented in the Highlands by 

 diminutive species (Cornus suecica, Eubus saxatilis, E. 

 Chamaemorus, and Betula nana). 



Several Vacciuiums are conspicuous subjects in the 

 formation of the dwarf shrubby vegetation of mountains. 

 The native evergreen-leaved species (V. Vitis-Idsea) is illus- 

 trated (Plate XXII., Fig. 1). 



Mat Growths. — Several plants form a dwarf layer of 

 interlacing, much-branched, woody shoots, which spread over 

 rocks. Some mentioned under shrubs must at times be 

 included here, for under certain conditions, and especially 

 when growing in exposed places, they become very dwarf, 

 spreading over, rather than rising from, the ground. Empetrum 

 nigrum and the Heather are plants thus varied in habit. 

 The mountain form of the Juniper, Juniperus communis var. 

 nana, is smaller than the ordinary form. Not infrequently 

 the Juniper occurs on rocks around which coarse Grasses 

 and Sedges luxuriate. Starting as a seedling, perhaps in a 

 very small crevice, the roots strike down into the slit, while 

 the branches spread over the surface of the rock. Here it is 

 quite safe from competing plants around. No seed can grow 

 on the rock covered by the branches, and the crevice where 

 the Juniper received its first start of life having been filled 

 up with the plant's growth, is inaccessible to other plants. 



Loiseleuria procumbens (Plate XXIII.), known as the 

 Scottish Azalea, has a somewhat similar growth to that of 

 the Dwarf Juniper. So flat and interlaced are its wiry-like 

 branches, that a plant may be lifted from the ground, rolled 

 up, placed in the pocket, and unfolded without breaking or 

 straining a shoot. The carpets of Loiseleuria sprinkled with 

 rose-coloured flowers in summer form one of the most charm- 

 ing features of Scottish Alpine plant-life. It is perhaps best 

 seen in the Grampian range, where the conspicuous mat 

 growths occur amongst Heather or on stones. 



Of non - evergreen mat growths none are more striking 

 in certain districts than Dryas octopetala, a well - known 



VOL. v. K 



