3o6 



The Irish Naturalist, 



[Dec, 



Rurnex Acetosella. 

 Empetnim nigriun. 

 Alyrica Gale. 

 Narthecium ossifragnm. 

 Junciis siipimis. 

 J. squarrosus. 

 Scirpus ccespitosus. 



Carex pilidifera, 

 C. binervis. 

 Airajlexiiosa. 

 Nardil s strict a. 

 Lomaria Spicant. 

 Lastnea dilatata. 

 Athyrhun Filix-famina. 



A scrutiny of this list might fairly be expected to show that 

 the majority of the Ox Mountains plants absent from Ben 

 Bulben are calcifuge species, that is to say, species which shun 

 the limestone, while they appear in full development on non- 

 calcareous soils. But we find that this is by no means the 

 fact ; for out of the forty-one species just mentioned only two 

 — Lathyrus macrorrhizus and Jasione 7no7ita7ia — can be classed 

 as decidedly calcifuge. When on the other hand we examine 

 the catalogue of Ben Bulben plants we find the following 

 twenty-two calcifuge species recorded for this eminently 

 calcareous district : — 



Cai^cifugk speciks found in Bkn Bulben District. 



Galium saxatile. 

 Vaccinitim Myrtillus. 

 Calluna vulgaris. 

 Erica cinerea. 

 E. Tetralix. 

 Digitalis purpurea. 

 Pedicularis sylvatica. 

 Polygonum Hydropiper. 



This full representation of the calcifuge group in a district 

 where the formation is almost purely limestone, would appear 

 at first sight to utterly discredit the classification of plants by 

 their apparent affection for, or aversion to limestone soils. In 

 reality, the constitution of the Ben Bulben flora furnishes no 

 argument against the validity of this classification, which is the 

 expression of a very well-grounded induction. The explanation 

 of the apparent anomaly is not far to seek. Ben Bulben, in 

 fact, even if we restrict the name to the great steep-scarped 

 rock-mass lying between Glencar on the south, and Glenade 

 and Gleniff on the north, so as to cut off all but the purely 

 calcareous formations, is capped for some eight miles with a 

 deep bed of peat ; and in this peat-cap the calcifuge species 

 find that neutral or non-calcareous soil which appears to be a 

 necessary condition of their healthy development. 



Having thus sketched the general features of the Ox 

 Mountains flora a few details may be given as to the more 

 interesting plants observed by us in our hasty survey. 



Trifollum medium, Iriiiii. — Frequent amongst Gorse, and in field 

 borders and on banks near Skreen and Dromore West. 



Prunus Padus, L<inn. — A single tree, apparently native, on the 

 rocky shores of Ivough Achree. 



