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THE BOTANY OF THE HONDDU AND GRWTNE 



VALLEYS. 



By the Rev. Adgustin Let, M.A. 



The extreme south-west district comprehended in the "Herefordshire Flora" 

 consists of hill and valley, which possess a higher average level than any other 

 district of the county. The hills form a rudely lozenge-shaped parallelogram, and 

 consist of ranges having a general direction of S.E. and N.W. These ranges are 

 all connected into a single plateau of high ground at their N.W. extremity, where 

 they suddenly cease, giving place to the valley of the Wye as it flows for five miles 

 N.E. from Three Cocks to Hay ; and to that of the smaller stream, the Llynfi, 

 which drains Llangorse Lake, and joins the Wye at Glasbury. The flank thus 

 formed is the finest and most abrupt in all the hills ; and the bold bluflfs, alter- 

 nating with shallow depressions on "cols," when ^newed from the neighbourhood 

 of the Three Cocks or Hay, give a very fine effect indeed, especially upon a 

 winter's day, when tipped or eyebrowed with snow. 



The shallow "cols" alluded to indicate the heads of the valleys, which, 

 parallel like the ranges of hills, all take their rise in the N.W. boundary of the 

 high ground, whence their streams flow S.E. until they reach the S.E. boundary 

 of the mountains, when they turn abruptly, two of them (the Grwyne fawr and 

 Grwyne fechan) S.W. to join the Usk ; two (the Honddu and Monnow) N.E. to 

 join the Dore from its Val d'Or, or " Golden Valley," and flow down to Monmouth 

 under the joint name of the Monnow. These valleys are all (at least all that I 

 know, for the valley of the Grwyne fechan I do not know) very similar in geo- 

 logical structure, in outward features, and in their Flora and Fauna. I suspect the 

 latter as well as the former to be full of interest— indeed, as far as the birds are 

 concerned, I know it to be so ; but I must leave that subject to be handled another 

 day by some one more competent than myself, and limit myself now to the 

 flowering plants and ferns only of the two interior of these valleys, the Honddu 

 and the Grw3me fawr, including the intervening ridge of the Ffwddog. 



To compare for a moment these two valleys : that of the Honddu (Afon ddu, 

 the Black Stream) is the larger, the longer, the deeper, but not the wider. Its 

 length from Bwlch-y-fingel, the col at which its N. branch rises, to Llanvihangel- 

 crug-corney, where it turns N.E., is about 10^ miles as the crow flies. The average 

 breadth of both it and the Grwyne fawr is, from edge to edge of the hill, about 

 1 mile. It is cultivated up to its division into two heads at Capel-y-Sin, or about 

 8i of its lOJ miles of length ; and above this also much of the land is enclosed, so 

 that the actual moorland in the valley forms an insignificant proportion of its 

 surface. The valley of the Grwyne fawr, the signification of which name I must 

 leave to Welsh scholars to elucidate, is somewhat shorter and much shallower, 

 though of nearly equal breadth. Its length from Blaen Grwyne, its N.W. col, to 



