(1) Mimuhit guttatiix is not native bv our mountain streams because, though 

 it came there by natural seed dispersal, the source of the seed Tvas a garden. 



(2) Fiiiffuicula grandiflora is not native in wild ground at Blackstairs, Co- 

 Wexford, because the roots were brouglit there from KeiTy by a botanist. 



(3) Equisetitm variegafiim is not native along the Royal Canal, though it lias 

 spread there naturally Iroiu native stations, because its habitat there is artificial. 



Such tests are often not easy to apply, but it seems certain that the attempt 

 should be made, for without such inquiry it would be impossil)le to study the 

 flora in the light of its past histoiy, or to attempt to use the evidence of the 

 plants for bygone changes in climate or iu the distribution of sea and land. 



In the following pages, then, a clear distinction is made between plants 

 believed to be aboriginal, and those which on any of the above counts owe their 

 l)resen(e in our district to human influence : the former being printed in Claren- 

 don type, the latter in Italic. In the case of tlie latter, plants which are con- 

 sidered as established in the area so long as present conditions (natural or artificial) 

 remain, appear in italics without brackets ; while the names of those which are 

 looked on as not established, as well as those which have been recorded in 

 error, are printed in italic within brackets. 



Mosses and Hepatics. 



The present publication differs from the Flora and its First Supplement 

 inasmuch as the Flowering Plants and Pteridophytes alone are dealt with, no 

 attempt being made to bring up-to-date our knowledge of the Mosses and Hepatics. 

 The recent death of the leading local workers at these groups. Canon Lett and 

 Eev. C. H. Waddell, is mainlj' responsible for this. But recent information 

 respecting the distribution of these plants is available — as regards the Mosses, 

 in Canon Lett's "Census Catalogue of the Mosses of Ireland" (Proc. R.I. 

 Academy xxxii. Sect. B, 1915), and as regards the Hepatics in the same writer's 

 "Catalogue of British Hepatics" (1904) and McArdle's "List of Irish Hepaticae" 

 (Proc. R.I. Academy ixiv, 1904). 



