77 



an immediate interest^those of the Black Mountain Group, lying in the three 

 counties of Brecon, Monmouth, and Hereford. Here we are upon quite a 

 different scale of mountain scenery. The cliffs are not precipices, but ranges of 

 rocks more or less precipitous, occupying the mountain side. They do not, of 

 course, present anything like the richness of the precipices we have been 

 enumerating ; yet they deserve comparison with them, by supporting, as far as 

 they go, a real cliff flora, distinct from that of the hills in general. Several of 

 these "Tarens" as they are called, belong to the Herefordshire Flora : (1) a well- 

 known and conspicuous one at Cwm-y-oy, which is, however, dry, and of little 

 botanical interest ; (2) one much richer, on the northern slope of the Ffwddog, 

 about three miles above Llanthony Abbey ; (3), a small, but interesting one on 

 the north face of the Hatterel range above Longtown, called the " Red Daren" ; 

 and (4) another interesting one in the little valley of the Olchon, some four miles 

 further to the north-west, which we may name the Olchon Daren. The last two 

 lie in Herefordshire proper. There are several others ; but the main cliff of the 

 whole range is undoubtedly " Taren r' Esgob," in the head of the right branch of 

 the Llanthony Valley. This lies wholly in Breconshire, and is the head centre of 

 the interest of the wild Flora and Fauna of the Black Mountain Group. All the 

 four la.st-mentioned face north-east. 



It is worth while to notice, in passing, that, out of the whole number of 

 cliffs here described, one only faces south (Cwm-y-oy Daren), and this one is the 

 poorest and driest of all. One faces west (the Carnedd Dafydd cliff). Two face 

 east (Clogwyn-y-Garnedd, and the Llyn Cau cliff). Eight face north or north- 

 east. That is to say (regarding only the cardinal points), out of 12, 8 have the 

 coldest aspects, 3 the intermediate, and 1 the warmest. I think that something 

 like these proportions are general in mountain cliffs ; and that this accounts in 

 part for the peculiarly boreal character of the flora which tliey maintain. 



It will be noticed that the chief districts of Wales, the cliff flora of which is 

 quite unrepresented in the above list, are (1) its north-east section, in Flint and 

 and Denbigh ; (2), its south-west peninsular in Carmarthen and Pembroke ; and 

 (3) its extreme south-east county in Glamorgan. Of the cliffs of these counties I 

 know nothing ; but the north-east section, and the county of Glamorgan should 

 certainly be added before any inductions with regard to the cliff flora of Wales 

 could be termed complete. They probably possess a cliff flora, to some extent, of 

 their own. 



Enumeration of 46 typical cliff plants, showing their distribution in Wales : — 



1. Thalictrum alpinum, L. 1, 2, 3. Present in the higher cliffs 

 of the Northern Group, absent from its lower cliffs, and from the Central and 

 Southern Groups. Present northwards in the English Lakeland, and in Scotland. 



2. Thalictrum minus, L., var. montanum. 2, 3, 4, 5, G. The 

 mountain form of Thalictrum. lainus is distinctly a cliff plant. Present in all the 

 cliffs of the Northern Group, in the Central Group, and at Craig Gledsiau in the 

 Southern Group, but absent from the Black Mountain. This cliff form reaches 

 its southern limit in Britain in Somerset. Abundant northwards, especially in 

 English Lakeland ; present in Scotland. 



