46 
FIELD MEETINGS, 1952 
Urwyne Fec-haii valley. An intensive search of the stream-bed ensued, 
in a valiant, hut unl’ortunately unavailing, effort to rediscover a raie 
moss, Bnjiim (jemmiparum , which was first observed many years ago by 
Augustin Ley in two places in the neighbourhood. 
In the evening, the party met once more at the Bear Hotel to discuss 
the work of the last few days and to bid farewell to Dr. Warburg with 
many thanks for his keen co-operation. 
Friday, 25th July. 
A small sti'eam, the Clydach, ihses on the dip slopes of Mynydd Llan- 
gattwg, flows through the busy colliery town of Brynmawr and instead 
of pursuing the usual course south through the coalfield, turns sharply 
east and tumbles down 1000 ft. or so in less than four miles in a series 
of fine waterfalls, rapids and deep inaccessible gorges. Considering the 
proximity of the industrial area, Cwm Clydach is remarkably unspoilt. 
Ecologically, Cwm Clydach is supremely important in South Wales, 
for, centred on the limestone, extending almost unaltered on to the 
grits above and the marls below is as fine and natural a beechwood as 
exists anywhere in Britain. On tlm cliffs rare Sorbus spp. flourish. In 
the deep shady wood Monutropa was seen. Beech is absent (except where 
obviously planted) west of Craig-y-Cilau where the species grows high 
on the cliffs near the tree-line. Traces of beechwood extend along a 
number of valleys into the southern part of the Black Mountains. 
Progress up the Clydach stream from Gihvern was slow and arduous, 
especially in the gorges where numerous diversions were necessary in 
order to progress at all. Even the less steep slopes had to be negotiated 
with caution. The many deep chasms along the gorge were especially 
noted for the luxuriance of the ferns and mosses. A railway line, which 
runs below the cliffs on the south side of the valley promised to supply 
a welcome route back to Gilwern. Though extensively quarried, the 
limestone precipices are still thickly clothed in beech and exhibit a pro- 
fusion of Sorbus amongst which at least three different species were 
noted — S. anglica, S. porrigeutiformis and S. leptnphylla. Along the 
railway. Geranium- somguineum is locally abundant, actually the only 
locality for the plant on the northern outcrop of the Carboniferous 
Jiiraestone. 
The evening was occupied by a symposium on the observations of the 
week, during which a very complete and balanced picture of the vegeta- 
tion and flora of the south-east portion of the National Park ai'ea was 
obtained. The next morning the meeting slowly broke up as, one .after 
the other, the members dispersed after general applause of the success 
of the first Junior Field Meeting. 
Some Notes on the Flora. 
It is difficidt to adequately summarise the floristic observations made 
by the party. Here are the salient features ; 
