44 
FIF.T.l) MRETINCS, 1 052 
Tile lake is ro]iute(l to be quite shallow, and the land rises so very 
graduallj’ from the lake edge that it is virtually impossible to approach 
the open water except at one or two iilaces. Along practically the whole 
of the shore, an extensive marsh and swamp stretches in places as much 
as 100 yards from firm ground to open water. The changes in vegeta- 
tion as one proceeds lakewards are gradual. The typical rich rye-grass 
meadow's and pastures pass into w'ater meadow's wdiere Gli/ceria and 
Jiincvs increase, and share the damper ground wdth a host of w’ell-knowu 
marsh species. Thal'utrum flavum is particularly prominent. Where 
the ground is perpetually w'ater-logged, sedges become dominant and 
form a belt of vegetation in w'hicb the giant buttercup (Ihtwii iiruhia 
lingua) is abundant. Here and there in the open spaces of muddy 
water are communities of Equhetum , Menyanthes, Iris and Sparguniinn. 
In deeper w'ater, the reed sw'amp comes into its ow'n. Phrag mites is the 
general dominant, but in places Scirpus tahernaemontani and Equise- 
fum limosuni form limited associations. At the few' places w'here the 
lake edges ai’e sloping .steeply enough to reduce the extent of marsh and 
swamp, the open-water communities could be viewed to advantage. 
Pal ygninnn a m ph ihi inn and Ni/inphoides peltatuni form the principal as- 
sociations. The lattei' has only recently been introduced into Tdyn Safad- 
dan but has established itself to such an extent that the dominance of 
Pulygomnn aniphihiiim is threatened. Submerged plants include Elodea 
in great quantity, and pondw'eeds are abundant. Duckweeds, including 
Leinna pal ynli/n:a ami f.. frisulca, are frequent on the w'ater near the 
banks. In places a marsh carr vegetation dominated by Alnvs and Salix 
riwinalis occupies rather steeper lake margins. Within the wood is an 
extraordinary mixture of herbs typical of deciduous low'land woods on 
the one hand and of marshes and even reed swamp on the other. 
The extremely rich and varied flora of Llyn Safaddan is associated 
with base rich w'ater, fed from the fertile marl country, and how' the 
vegetation contrasts w'ith the sterile oligotrophic tarns high up in the 
mountains and on the peat lands ! 
The deep canal-like Afon Llynfi flow'ing from the lake on its w'ay to. 
the Wye is fringed for many hundreds of yards by reed sw'amp while 
the w'ater-surface is often completely hidden by the leaves and blossoms 
of water-lilies. 
Wednesday, 23rd July. 
On Tuesday evening the party met at the Rear Hotel to w'elcome 
Dr. Warburg on his arrival from Oxford. Unanimity w'as expressed on 
the suggestion that a second visit be made to Craig-y-Cilau on the fol- 
low'ing day. The party were keenly interested in elucidating the rela- 
tionships of the Sorbus spp. so w'ell represented there. Dr. Warburg 
determined the species as Eorhus aucupnria, S. miivima, E. leptaphylla . 
E. porrigentiformis, S. anglica and E. rupicola. Other interesting 
plants seen here were Polygonatum odorotvm and Cirraea alpina, the 
former on the cliffs and the latter in the scree. After a thorough .search 
of the cliffs, the party descended to the base w'here a small stream 
