A HISTORY OF SURREY 



The ten districts into which the county is divided are : (i) Black- 

 water; (2) Bourne Brook; (3) Upper Wey ; (4) Lower Wey ; (5) Upper 

 Mole; (6) Lower Mole; (7) Hogg's Mill; (8) Wandle ; (9) Medway 

 all of which drain into the river Thames ; and (10) Arun, draining into 

 the English Channel. These are now described, and lists of their rare or 

 characteristic species are appended. 



1 . BLACKWATER 



This district is bounded on the south by a line leaving the Hants border at Lower Old 

 Park, and extending to a point on the Hog's Back a little north-east of Scale ; thence the 

 eastern boundary runs past Ash Green station, the Fox Hills and Chobham Ridges to the bor- 

 ders of Berkshire. The other boundaries are formed by the counties of Hants and Berks. 



This is a small district, comprising as it does only a limited portion of the river basin. 

 For the most part it consists of more or less barren and uncultivated sandy heaths, interspersed 

 with considerable tracts of deep and dangerous peat bog. On the former the three heaths 

 (Calluna vulgaris, Erica cinerea, and E. tetralix), with the furze (Ulex eurepaus and U. nanus) 

 and the broom (Cytisus scoparius), form the bulk of the vegetation, together with extensive 

 pine woods which cover much of the higher ground. A boggy wood adjoining the railway 

 and canal near Ash Vale is remarkable for the various species of sedges which grow together 

 there and which are not usually associated, such as Carex elongata and C. riparia ; the latter 

 however appears rarely to flower, so that its identity was not certainly made out for several 

 years. In the alluvial meadows by the river Blackwater between Frimley and Blackwater 

 there occurs a small quantity of the great burnet (Sanguhorba officinalis), not known elsewhere 

 in Surrey ; while in a deep bog near the canal at North Camp the slender cotton-grass 

 (Eriophorum gracile) grows in abundance, its discovery here restoring the species to the county 

 list. The generally boggy nature of the land is indicated by the occurrence of such plants as 

 the meadow thistle in several places on the railway banks, while the alder (Alnus glutinosa) 

 quite replaces the more familiar hawthorn in long sections of the railway hedges. As an 

 absentee from the greater portion of the district the common primrose (Primula vulgaris) may 

 be mentioned ; this plant, so widely distributed over the county and often so abundant, is 

 quite unable to exist on the hot dry sand of the Bagshot series, and is only found in the 

 neighbourhood of the chalk with the exception of one locality near North Camp, where it 

 occurs on alluvial soil by a small stream. 



The following are among the more remarkable and interesting plants found in this 

 district : 



Ranunculus tripartitus, DC. Potamogeton nitens, Weber. 



var. intermedius, Hiern. ruiescens, Schrad. 



Cerastium tetrandrum, Curtis trichoides, Cham. 



Sanguisorba officinalis, L. Scirpus pauciflorus, Lightf. 



Anthriscus vulgaris, Pers. Eriophorum gracile, Koch 



Pyrola minor, L. Carex elongata, L. 



Wahlenbergia hederacea, Reich. canescens, L. 



Utricularia neglecta, Lehm. fulva, Good. 



minor, L. Oederi, Auct. 



Myrica Gale, L. Agrostis setacea, Curtis 

 Potamogeton heterophyllus, Schreb. 



2. BOURNE BROOK 



The Bourne Brook district is bounded on the west by district i, on the north and north- 

 east by the county of Berks and the river Thames, and southwards by a line starting from 

 Chobham Ridges and passing near Bisley and through Horsell to a point on the river Thames 

 about midway between the mouths of the Bourne Brook and river Wey. The stream from 

 which the district takes its name rises close to the village of Bagshot, uniting a little north of 

 Horsell with another branch which rises on Bisley Common, and flowing in a north-easterly 

 direction to its junction with the river Thames. The general character both of the soil and 

 vegetation is very similar to that of district I, except that the bogs are more extensive. One 

 feature may be noted which is quite unique in the county. As one crosses the wide expanse 



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