136 



Proceedings of the Royal IrkJi Academy. 



FLORISTIC JfOTES. 



The publication recently of Mr. Colgan's Flora of the County 

 Did}li7i places at the disposal of the botanist a full, detailed account of 

 the nature and distribution of the higher plants inhabiting the 

 county. The notes which follow are mainly drawn from this Avork. 

 Dublin lias an exceptionally ricli flora in comparison with other Irish 

 counties (750 species, a total surpassed only in Antrim and Down) ; 

 but its exceptional richness lies chiefly in that class of plants with 

 which the present study is least concerned — namely, those which more 

 or less certainly owe their presence to man's operations. Over one- 

 fifth of the total flora is included in the non-native section. These 

 are almost without exception lowland species, dwelling in the farm- 

 land and urban areas, and not affecting the native associations of the 

 hills, with which we shall chiefly deal. The county is practically devoid 



Scale of SptciES 



O 100 zoo iOO ♦OO JOO too TOO 60O 



Fig. 1. 



of lakes and low-level bogs, and its flora consequently poor in hydro- 

 phytes and bog-plants. In maritime plants it is very rich. It is 

 also relatively rich in plants having in Ireland a southern distribution, 

 and also in those whose range in Great Britain is southern ; in northern 

 plants it is distinctly weak. Coming to that portion of the county 

 which is included in our survey, its area is about two-fifths of the 

 whole, and its flora may be roughly taken as 650 species. Its coast- 

 line offers no opportunity for the development of the rich maritime 

 flora of the county, but its urban and farm-land areas possess a large 

 flora of native and non-native plants. It is in its mountain land, 

 however, that it chiefly differs from the rest of the county. While 

 the foot-hills and glens contain a number of interesting species, the 

 hills themselves are singularly poor in mountain plants. For instance, 

 only four of Watson's Highland type occur — namely, Saxifraga 

 stellaris, Vaccinium Vitu-Idmay Carex aquatilis^ Selaginella selaginoides. 



