A HISTORY OF DEVONSHIRE 



study botanical convenience ; they are moderate in number, not very 

 unequal in size, easy to be defined, and their limits can be traced on the 

 ordnance maps ; they are each named after a principal town therein, as 

 follows : I, Barnstaple ; 2, Torrington ; 3, South Molton ; 4, Exeter ; 

 5, Honiton ; 6, Torquay ; 7, Plymouth ; 8, Tavistock. 



The Barnstaple district contains the whole of the north coast ; the 

 Honiton, Torquay and Plymouth districts together contain the south 

 coast ; the Barnstaple district is entirely and the Torrington and South 

 Molton districts are mostly north of the watershed ; the Honiton and 

 Plymouth districts are entirely, and the Exeter, Torquay and Tavistock 

 districts are mostly south of the watershed. 



The most fertile districts are those of Exeter, Honiton and Ply- 

 mouth ; those of Torquay, Barnstaple and South Molton are about the 

 average of fertility ; and those of Tavistock and Torrington are the most 

 barren. Chalk is found only in the Honiton district over a limited area. 



The summary on the opposite page, showing for each natural order 

 the number of genera and species in the county, is drawn up generally 

 in accordance with Hooker's Students Flora of the British Islands (ed. 3), 

 but the census of species is calculated on the scale of the London Catalogue 

 of British Plants (ed. 9). The enumeration in the Catalogue included a 

 considerable number of sub-species, colonists, aliens and casuals ; it is 

 therefore necessary for the sake of just comparison to count for the 

 purpose of the census all such like plants occurring in Devonshire under 

 circumstances similar to those which occasioned their inclusion in the 

 Catalogue ; but where the circumstances are substantially different they 

 are not counted. The setter-wort {Helleborus fcetidus) is regarded as 

 native in the chalk pastures and thickets of southern and south-eastern 

 England, but in Devon it occurs only as colonist or casual ; it is 

 therefore not counted in the census. 



The American cress {Barbarea prcecox) is an alien, but is well estab- 

 lished in many parts of England and as such is mentioned in the 

 Catalogue ; it occurs in like manner and is spreading in Devon, and is 

 therefore counted. 



Barbarea intermedia is treated in the Student's Flora only as a sub- 

 species occurring in cultivated fields, but in the Catalogue it is numbered 

 as a species ; in south Devon it occurs as a colonist, and under these 

 circumstances it is counted in the census. 



The cushion-pink or moss-campion {Silene acaulis) according to Ray 

 was found in Devon by Mr. Gidley, and Hudson in 1778 recorded it as 

 occurring on Dartmoor. There is no modern record of its occurrence 

 there, and there is reason to suspect that some other plant was intended 

 by the old authorities ; it is therefore not counted. 



The bryony {Bryonia dioica) has several times been reported as 

 occurring in the county. Polwhele in his History of Devonshire, i. 96 

 (lygy), under the synonym of B. alba, stated that ' the beautiful berries 

 of the bryony or wild vine very much ornament our hedges during the 

 winter months, and the exprest juice is formed into an ointment as a 



58 



