ON THE YORKSHIRE COAST 93 



Prunus spinosa, Blackthorn or Sloe. Well 

 known as a hedge plant. Deciduous ; Britain. 



Pseudotsuga Douglasii (syn. Abies Douglasii), 

 Douglas Fir. A magnificent species. It grows 

 when sheltered near the sea in Yorkshire. The 

 tops are liable to injury when reaching exposure 

 on high lands. It is found in large forests on the 

 Rocky Mountains. Evergreen ; North America, 

 1826 ; height 100 to 180 feet. 



Pyrus Aria, White Beam Tree. Very hardy 

 and good for exposed positions by the sea. It is 

 useful as affording shelter to other trees, and is 

 equally good on light or heavy soils. It grows 

 well in moist soils, and makes the best shelter 

 when cut down to stool out. Deciduous ; indi- 

 genous to Britain. 



Pyrus aucuparia, Mountain Ash or Rowan 

 Tree. Another very hardy and handsome tree, 

 standing exposure well. Deciduous ; Britain. 



Pyrus communis, Wild Pear. Very hardy, and 

 will grow in the most exposed places, but under 

 such conditions it loses its erect habit of growth. 

 Deciduous ; Britain. 



Pyrus Mahis, Crab, Wild Apple. Very hardy 

 on dry hills and slopes at high elevations. Decidu- 

 ous ; Britain. There are several highly orna- 

 mental flowering species. 



Pyrus prunifolia, Siberian Crab. Highly 

 ornamental. Will grow well under exposure by 



