INTRODUCTION. 3 



J. G. Baker's books, " North Yorkshire," the " New Flora of 

 Northumberland and Durham," and the " Flora of the 

 English Lake District." In this work I have only numbered 

 the species that have a reasonable claim to be regarded as 

 wild plants in Derbyshire. A break in the regular sequence of 

 the figures consequently indicates that plants that grow wild 

 elsewhere in Britain are not found in this county. The 

 plants whose names are given in italics are considered as 

 ambiguities and doubtful, respecting which further informa- 

 tion is required. 



Classes of Citizenship. These are to be understood as used 

 in the same sense as in Watson's " Cybele Britannica," 

 where they are fully defined and explained. By a "Native" 

 is meant a plant which, so far as present appearances show, 

 has established itself quite independently of man's interven- 

 tion. By a "Colonist" is meant a well-established weed of 

 corn fields and arable land; by a "Denizen," a plant that 

 now looks quite wild, but may, perhaps, have been originally 

 introduced by human agency; and by an "Alien"*, species 

 established less thoroughly, which, without doubt, has 

 strayed from cultivation. 



Types of Distribution. The types of distribution, as 

 worked out by Mr. Watson, furnish a ready means of indi- 

 cating the distribution of species through Britain as a whole. 

 The types are as follows, viz.: 



1. British Type. Species which are spread at shore-level 

 through the length and breadth of the island. 



2. English Type. Species which have their headquarters 

 in the south of England, and become rare and run out in the 

 north of England or south of Scotland. 



3. Germanic Type. Species that have their headquarters 

 in the east of England, and become rare and run out 

 altogether in the western counties. 



4. Atlantic Type. Species that have their headquarters 

 in Wales and the west of England, and run out eastward. 



5. Scottish Type. Species that have their headquarters in 

 Scotland, and run out in the north of England. 



6. Highland Type. Species that have their headquarters 

 in the Scotch Highlands, and grow southward only amongst 

 the high mountains of the north of England and Wales. 



7. Intermediate Type. Species that have their head- 

 quarters in the north of England. 



8. Local Type. Species too local to be classed under any 

 of the preceding types. 



The following table, therefore, will show at a glance how 

 the plants of Derbyshire are spread through the rest of 



B2 



