PLANT DISTRIBUTION AND ASSOCIATIONS. XXXV11. 



or the upper part of Luddenden Dean, and many others are of 

 this type, or, like Rough Hey Wood, Triangle, approach it more 

 or less nearly. Either the oak is the dominant tree, or the oak 

 and birch almost equally numerous, or occasionally the birch 

 is dominant, but no other deciduous trees are at all prominent. 

 The underwood is insignificant, holly, willow, mountain-ash, 

 being the chief representatives. Brambles aie prominent, and 

 ivy, honeysuckle, dog rose, raspberry, and sloe frequently 

 present, but the most important shrubs are bilberry and 

 heather. Bilberry almost always covers extensive areas, and 

 often occupies the surface of the rocks, and heather is subord- 

 inate ; but whenever the wood becomes more open their 

 positions are reversed, so that on the edges and open banks 

 heather is dominant. But these two shrubs do not occupy the 

 whole ground, they share it with bracken and with certain 

 grasses, so that each in turn is dominant and excludes the 

 others. The grass which is most obtrusive is Deschampsia 

 flexuosa, and associated with it are Festuca ovina, Navdus stvicta, 

 and Agvostis vulgaris. Often Holcus mollis forms an extensive 

 stretch of itself. Bracken is the only fern to occupy much 

 ground, but lady-fern, male-fern and Lastvaa dilatata are by no 

 means absent. The bluebell nearly holds its own in these 

 woods at times, but the other herbaceous plants are very much 

 diminished in number and quantity. The most characteristic 

 are Pontentilla Tovmentilla, Galium saxatile and cow-wheat, 

 Melampyvum pvatense. Such composites as Solid ago Vivgauvea 

 and HypochcBvis vadicata occur on open banks with hair bell, 

 (Campanula votundi folia), and woodsage. Cavex piliilifeva is the 

 most frequent sedge, and a number of mosses are frequently 

 met with. The wintergreens, Pyvola media and minor also 

 appear to belong to this association, but both are rare. 



Occasionally the oak gives place to an almost pure growth 

 of birch, which admits more light, and therefore gives greater 

 encouragement to xerophilous societies like heather, bracken, 

 &c. But, naturally, whether it be oak or birch, the wood is 

 sure to furnish marshy places, along the course of some small 

 stream, where the moisture-loving species already mentioned 

 will be found. 



The woods above Hebden Bridge, where Scots Pine and 

 Austian Pine, and to a smaller extent Larch and Spruce 

 Fir have been planted, conform generally to the type of oak 

 wood on a dry rocky slope, and what has been said of that 

 type applies equally well to them, whether they are, as usual, 



