268 Mr. H. T. Mennell's notes on the Plants of Cader Idris, Sc. 



mountains, where tlie less hardy but much more vigorous and 

 aggressive flora of the lowlands cannot follow it ; and it may be 

 that the warmer winter climate of the Welsh Alps, open to the 

 warm Atlantic gales, enables this lowland flora to flourish at a 

 higher elevation, and to wage war successfully with the alpine 

 plants, and this may account for the comparative poverty I have 

 alluded to. 



On the wet rocks of Llyn-y-Cau, below Cader Idris, on the 

 fine crags of Cwm Glas and of Crib-y-disgail, parts of 

 Snowdon, as well as on the slopes of the Glydrs, and especially 

 in the chasms of Twll Dhu, many of the most striking and 

 beautiful of our alpine favourites may, however, be found in 

 abundance. Of these, the most noticeable are Saxifraga oppositi- 

 folia, Silene acaidis, Rhodiola rosea, with many varieties of the 

 mossy saxifrage, Saxifraga hypnoides and its forms, mingled 

 with some less distinctly alpine plants, such as Trollius europmus, 

 the globe flower ; a very erect short stiff form of Geum rivale, 

 Thalictrum montanum, and others. A handsome moimtain variety 

 of the common thrift also attracts attention. The parsley fern is 

 very abundant on both mountains, as also is Lycopodium alpinum ; 

 and the filmy fern, Hymenophyllum wilsoni, clothes the wet rocks 

 about the waterfalls. 



In mountain pools, on the flat ground above the Devil's 

 Kitchen, we found the curious aquatic cracifer, Subularia aquatica ; 

 and on the bare rocky ribs, running down from the base of the 

 Glydr Fach to the Devil's Kitchen, a few plants of Hieracium 

 liolosericeum, the only one of the " alpinum " section of the hawk- 

 weeds we noticed. This genus is much less abundant, both as 

 regards species and individuals, than in Scotland or the North 

 of England. The most abundant species at a high elevation on 

 both mountains, but especially on Cwm Glas, was Hieracium 

 bifidum, one of the several species formerly included under 

 H. pallidum. On slaty debris on lower levels, near Tal-y-Llyn, 

 Cader Idris, a form was found, which may prove to be H. ovarium, 

 a species very recently identified as British. 



I was much interested in observing on the hill sides above 

 Bethgelert, and also, though less conspicuously, elsewhere, 

 '♦ Fairy Eings," as they are called, formed entirely of Lycopodium, 

 alpinum. One of these that I measured was 16 yards in diameter, 

 the outer ring was absolutely perfect, and like a box-edging ; 

 mside the ring were scattered plants of the Lycopodium, much 

 less vigorous, and many of them withering. 



From the botanist's point of view, however, our best find was 

 Alisma, or Elisma nutans, in a lakelet near Dolgelley. This very 

 rare and interesting plant grows in two or three feet of water ; 

 at the base, rooted in the mud, is a tuft of slender grass-hke 

 leaves, thence rise to the surface slender dehcate pedicels, 



