11] WOODLAND ASSOCIATIONS 65 
all probability, either been planted, or they are the descendants 
of planted trees. The latter is much the more rare occurrence, 
as few pine seedlings are met with in this district. 
AsH Woops OF F'RAXINUS EXCELSIOR 
Ash woods are characteristic of the slopes of the limestone 
hills of the west and north of England. In previous British 
vegetation memoirs, woods of this type have been described on 
the limestone of the mid-Pennines (Smith and Rankin, 1908), 
in Westmorland (Lewis, 1904 a), and in Somerset (Moss, 1907 a). 
They do not appear to have been described by continental plant 
geographers. Smith and Rankin (1903: 168 et seg.) mentioned 
three sub-types. The first of these, which they termed “ scar 
woods,” occurs on the slopes of hills of the Carboniferous Lime- 
stone: such “scar woods” are more of the nature of scrub than 
of woodland. “The hazel [Corylus Avellana] is the dominant 
element most commonly found ; but the ash [Fraainus excelsior] 
occurs frequently, and sometimes close enough to reduce the 
hazel to a subdominant form....As a rule, the ash occurs but 
sparingly, because, being almost the only timber tree in the 
limestone dales, it is generally removed. In this district, few 
of the woods receive any attention; and little is done to check 
disforesting. Almost all the scar woods are therefore to be 
regarded as shrubby thickets” [1.e., as scrub]. These ash and 
hazel scrubs are interesting in that they still furnish the habitat 
of that rare British orchid, the lady’s slipper (Cypripedium 
Calceolus). The second sub-type mentioned by Smith and 
Rankin occurs at lower levels on the Permian or Magnesian 
Limestone and in the bottoms of the dales of the Carboniferous 
Limestone, and consists of ash woods which have been much 
altered by planting beech, oak, sycamore, pine, and larch. 
The third sub-type is termed a “hazel copse of the Permian,” 
and is made up of scrub occurring on the Permian limestone. 
Lewis gives only a brief account of the woods of the district 
which he investigated; and it is not easy to relate them to 
general woodland types. However, the “birch woods” men- 
tioned by him (1904 a: 319), judging from their occurrence at 
comparatively high altitudes on limestone and from the list of 
associated species, would appear to belong to the general ash 
M. 5 
