II] WOODLAND ASSOCIATIONS 63 



Very few of the rare and characteristic herbaceous species 

 of the Scottish birch woods occur in Great Britain so far south 

 as Derbyshire. For example, the following species, which 

 occur in the Scottish birch woods (R. Smith, 1900 6) are 

 absent from Derbyshire : 



Pyrola secunda Linnaea borealis 



P. rotundifolia Corallorrhiza trifida 

 Moneses uniflora ( = C. innata) 



( = M. grandiflora) Goodyera repens 



Of the above, the coral-root stops at the Border : Goodyera 

 almost stops at Cumberland, but has outlying stations in 

 Yorkshire and Norfolk : Moneses (Pyrola) uniflora is unknown 

 in England : P. secunda and Linnaea are rare in northern 

 England ; and P. rotundifolia is a very local plant throughout 

 southern Britain. Listera cordata and Trientalis europaea, 

 which are found in birch woods in Scotland, exist on the 

 Pennines only as moorland plants 1 ; and, even on the moors, 

 they are rare and local. Pyrola media and P. minor appear, 

 in fact, to be the only species of this class which are typical of 

 both the Scottish birch woods and the upper woodland zone of 

 northern England ; and even these species are rare and local 

 throughout the whole of England. 



The Primitive Birch-Forest 



Judging from the timber which is not infrequently found 

 buried under the peat of the Pennines, it is certain that in former 

 times a very extensive upland zone of birch woods existed on 

 the Pennines; and the meagre birch woods which now occur 

 on the Pennines are to be regarded as the vestiges of a former 

 widespread plant association (cf. Smith arid Rankin, 1903 : 160). 

 Although birches are quite commonly met with under the 

 peat on certain of the moors of the district, one hesitates to 

 refer to such a layer as a continuous forest bed. The layer is 



1 It has recently been stated (Williams, 1910 : 127) that Trientalis europaea 

 grows "in woods" at Halifax, which is the southern British limit for this plant. 

 As a matter of fact, the plant in that locality is confined to a small space where 

 it grows among bilberry and mat-grass on a treeless hill side. Wheldon and 

 Wilson (1907: 239) state that on the Pennines farther north the plant grows 

 on "moorlands amongst bilberry, bracken, and heather." 



