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JUNCUS TENUIS Willd. IN NORTH WALES. 

 By J. Lloyd Williams. 



Mr. Arthur Bennett (Jouni. Bot, 1895, 39) raises tlie interesting 

 question whetlier Juncus tenuis is a recent introduction. He draws 

 attention to the British and foreign records given, and the plants 

 said to be associated with it, and invites further details respecting 

 these points. A fuller description of the Portmadoc locality, where 

 the plant was found by the Rev. W. H. Painter and the writer 

 (Jouni. Bot. 1891, 120), and of two new localities in the same 

 district, may assist in throwing light on this question. 



The Traeth Mawr is a fiat valley extending inland for about six 

 miles. The river forming the boundary between Carnarvon and 

 Merioneth runs through it. As late as the close of last century it 

 was partly covered by the sea. Asplenium marinum grows even now 

 on some rocks at the very head of the valley above the road from 

 Beddgelert to Tanybwlch, while Armeria vulgaris, Silene maiitima, 

 Asplenium lanceolatum, and other littoral plants are found in various 

 places round the valley and on the islet-like rocks rising out of it. 

 All this shows that at a comparatively recent period the whole 

 valley must have been a land-locked bay. About the beginning of 

 the century the Portmadoc embankment was built and the land 

 reclaimed, with the exception of a small portion just within the 

 embankment, which is always covered by a varying amount of 

 brackish water. Near this, such plants as Carex (Ederi, C. extensa, 

 Trifjlochin, &c., grow, while the remainder of the land as far as the 

 railway running parallel with the embankment is almost entirely 

 occupied by a very rough pasture full of gorse and tufts of Juncus 

 communis, J. maritimus, &c. The soil is sandy, but not marshy. 

 Juncus tenuis is confined to the cattle tracks which intersect this 

 portion, and it extends along several of them for twenty or forty 

 yards. I failed to find it in the wetter parts near the water or in 

 the better land on the other side of the railway. On subsequent 

 visits with botanical friends, we had some difficulty in finding the 

 plant again. The part where it used to flourish best had been 

 railed-off from the cattle, the tracks had become overgrown with 

 herbage, and the Juncus had nearly all disappeared. We, however, 

 found it growing plentifully in the new tracks which had been 

 made by the cattle. 



Last summer, as Mr. D. A. Jones, of Harlech, and I were 

 crossing the Traeth along a grassy footpath opposite the village of 

 Prenteg, about two miles further inland than the above locality, we 

 came upon a fairly large number of fine tufts of the rush. It is a 

 noteworthy fact that the only portion of the footpath occupied by 

 the plant was a part along which cattle were in the habit of passing 

 to and from a farmyard. Here again we were on reclaimed land, 

 and the soil was sandy and not wet. Soon after this, Mr. Jones 

 sent me specimens from above Harlech, in the county of Merioneth, 

 a few miles to the S.E. of Portmadoc. The following is his de- 

 scription of the locality : — " The plant grew about 2:^ miles above 



