PKEFACE. 



senting themselves elsewhere within the realm in situations less 

 open to suspicion. The line of demarcation cannot be so 

 exactly drawn as that, whilst it shall embrace none but plants 

 incontestably native to the soil, it shall not exclude others for 

 the rejection of which it would be difficult to assign a sufficient 

 reason. After all, we may perhaps with truth assert of this 

 island, in reference to the small amount of introduced or natu- 

 ralized species it contains, that which the philosophical 

 Wahlenberg reports of his own country (Sweden), " Vix enim 

 uUa alia existit terra, tam bene perseverata, in qua vegetabilia 

 spontanea tam preevaleant et ab adventitiis tam parum pre- 

 mantur." * 



One chief obstacle in the way of accurately distinguishing 

 the genuine plants of a country from those of extraneous ori- 

 gin arises from the very different ideas entertained of the term 

 " wild " amongst such as contribute to the general stock of 

 information on this head from local sources. With some, the 

 occurrence of a single specimen beyond the precincts of a gar- 

 den or other cultivated spot is a sufficient claim to citizenship ; 

 and if gathered in greater abundance there can be, in their opi- 

 nion, no reason whatever for the exclusion of the species. 

 Happily, observers of this class are not numerous, and a little 

 experience soon teaches them more caution in their con- 

 clusions. 



Others (and these constitute a majority) are so sceptical as 

 to look with an eye of suspicion upon, and even reject as aliens, 

 a large proportion of species that have been long recognized 

 and admitted by common consent into our indigenous cata- 

 logues ; and to such it must be conceded that, however mis- 

 taken may be their opinions in many instances, they at least 

 err on the safe side. In accordance with my own views on this 

 head is the practice and opinion of Professor Fries. 



" Bene novi aliis placuisse banc plantam exclusam, illam 

 additam, in his suo utantur judicio ; equidem vero non aliorum 

 commentis, sed mese experientise indulgere debui. Eas dico 

 plantas indigenas-, quae per longam annorum seriem sine omni 

 cultura intra provinciam copiose et definito loco propellarunt 

 et quotannis sunt multiplicatee ; exclusis igitur omnibus una 



* Fl. Suecica, vol. ii, p. vii. 



