4 THE FLORA OF DERBYSHIRE. 



Britain, and how the flora of this county compares with that 



of the whole island : 



Britain. Derbyshire. 



British 532 532 



English 409 282 



Germanic 127 14 



Highland 120 9 



Scottish 81 30 



Atlantic 70 3 



Intermediate ... 37 16 



Local 49 3 



*Total 1,425 889 



Zones of Temperature and Altitude. By "range" is meant 

 range in altitude above sea-level, and by the figures 1-2-3 the 

 zones of altitude in which the plant grows in Derbyshire. 

 For tracing out the vertical range of species Mr. Watson 

 divided the surface of Britain into two "regions" and six 

 "zones" of temperature. The two regions he called 

 "Agrarian" and "Arctic." The Agrarian includes the whole 

 surface of the island at sea- level and as far up the hills as 

 arable cultivation is possible. This is up to about 600 yards 

 above sea-level in the north of England and 400 yards in the 

 Scotch Highlands, whilst all above this belongs to the Arctic 

 region. These two regions he divided each into three zones, 

 Super-agrarian, Mid-agrarian, and Infer-agrarian ; Super- 

 arctic, Mid-arctic, and Infer-arctic. Of these six zones only 

 the Agrarian are represented in Derbyshire, the highest hill 

 being only 1,981 feet high, whilst the lowest land is about 

 150 feet above the sea-level. I begin to count from below, 

 and my zone 1 corresponds with Watson's Infer-agrarian 

 zone ; my zone 2 to his Mid-agrarian zone ; and my zone 

 3 to his Super- agrarian zone. 



Zone 1. Infer-agrarian zone of Watson. This embraces 

 all the low-lying part of Derbyshire, and is marked by the 

 prevalence of Convolvulus sepium, Bryonia dioica, 2'amus 

 communis, Acer campestre, Rhamnus cathartic us, and Cornus 

 sanguinea. 



Zone 2. Mid-agrarian zone of Watson. This descends, 

 according to Mr. Baker, to 150 yards and ascends to 350 

 yards in Derbyshire ; is marked by the plants given above 

 occurring in less abundance than in the lower zone, and by 

 the cessation of Ulex and the fruticose Rubi in the open 



* The above summary of classes of citizenship, &c., is extracted 

 from Mr. Baker's " Flora of the Lake District," pp. 2-4. 



