14 ALIEN FLORA OF BRITAIN 



Armoracia rusticana, L. Native in Eastern Europe, 

 It is usually recorded as an escape from cultivation^ 

 but Schur {Fl. Transsilvanice, p. 67) records it on 

 stream banks and in marshy meadows, and it may pos- 

 sibly be more widely distributed in such situations in 

 Central and Southern Europe than the Floras would 

 indicate. The plant certainly becomes more and more 

 obviously associated with horticulture north-westwards. 

 In the British Isles it can hardly be called naturalised, 

 seldom, if ever, producing seed, and never being found 

 far from the places where it has been cultivated. 



Barbarea prsecox, R. Br. Native in damp grassy 

 places, on river banks, &c., in Southern Europe. It is 

 fairly common in Britain, but always under suspicious 

 circumstances, as records also show it to be in the whole 

 of Northern Europe. It was formerly much cultivated as- 

 a salad plant, and it doubtless owes its presence here and 

 in North America, where it is also naturalised, to this use. 



[Barbarea stricta, Reich. Native by rivers and similar 

 places throughout Northern Europe, Asia, and North- 

 West America. It is found in these situations in Eng- 

 land, and any statement as to its exotic origin in such 

 habitats would have to be supported by very strong 

 evidence. Such statements are to be found in many 

 local Floras, but they are as a rule insufficiently sup- 

 ported. The species may certainly in some cases be 

 introduced, but its claim to be a native of Britain is not 

 weakened thereby.] 



Boreava orientalis, Jaub. and Spach. A Syrian 

 species received with other grain-imported aliens from 

 Burton. 



