THE DISTRIBUTION OF LIVING PLANTS. 121 



later blooming Hare-bell {Campanula rotundifoh'a), and the 

 rare Helleborine (Cephalanthera ensifotia), with its pure 

 white blossoms and long narrow leaves, and round about 

 Evershot the even rarer Great Bell-flower (Campanula latifolia], 

 Among the plants of larger growth may here be mentioned the 

 Wild Service tree (Pyrus torminalis] near the boundaries of 

 Cranborne Chase ; and on the extreme south-west and south 

 slopes of the central Dorset range will be seen the Musk Orchis 

 (Herminium Monorchis] rearing its slender spike of yellowish green 

 flowers. The Bee Orchis (Ophrys apifera) is commonly found at 

 the base of the chalk downs in Purbeck, and many other species 

 of Orchid may often be met with on the calcareous soil of the 

 district under consideration. The Dwarf Gentian finds a 

 suitable habitat in the short grass of the downs, as also the rare 

 Chalk Milkwort (Polygala calcarea}. Curtis' Mouse-ear Chick- 

 weed (Cerastium pumilum\ though very rare, may be found on 

 the chalk downs. Common Centaury grows in open spots, 

 whilst different species of Crane's-bill keep chiefly to hedge- 

 banks, road- sides, and the borders of woods and meadows. 

 Traveller's Joy (Clematis vilalba\ though chiefly located on chalk, 

 is also found on oolite, as in the Weares, Portland ; but not 

 on the Tertiary bed in the south-east of the county, nor usually 

 on the heavy clays of the west and south. The Wayfaring Tree, 

 or Mealy Viburnum ( Viburnum lantana\ which gets its name 

 from the soft mealy down covering its young shoots and 

 leaves, occurs principally on chalk or limestone, whilst the 

 common Guelder Rose may be found frequently on most soils 

 other than the sandy beds. The Common Flax (Linum 

 usitatissimuni} is somewhat rare, but has been found between 

 Evershot and Cattistock, and also in the south-western Lias 

 district around Bridport. 



There is, perhaps, no occasion to mention more than a few 

 other plants, whose growth depends chiefly on the calcareous 

 soil of this part of Dorset, such as : The Musk Mallow 

 (Malva moschata) with its crowded head of large rose-coloured 

 and sometimes white flowers, the Milk Vetch (Astragalus 



