A BOTANICAL TOUR THROUGH SOUTH WALES, &C. 297 



frond convex, hemispherical, lessening in thickness from the centre to the cir- 

 cumference. Frond exceeding two inches in diameter, skin thick and slightly 

 rugose, substance beneath of the same dark olive-green hue, jelly-like, and semi- 

 transparent. Unattached upon the limestone slabs near the water, but not im- 

 mersed in it. I brought a specimen home with me wrapt in leaves, and placing 

 it in water preserved it for three weeks, but no hue was imparted to the water 

 in which it was kept. It finally dried up, preserving its outline on a sheet of 

 paper, to which I transferred it. This curious plant somewhat resembles, though 

 evidently distinct from, Palmella montana (Ulvamont, Eng. BoL, 2193), which 

 Lightfoot mentions as used by the Highlanders, who wash it, rub it between 

 their hands in water, and make a paste with it, with which they purge their 

 calves. In form it approaches the largest figure of Rivularia calcarea in Eng. 

 Bot., t. 1799, which Sir J. E. Smith calls a "singular production," reported by 

 several friends to have been found " about many water falls in North and South 

 Wales, Shropshire, &c." Smith describes this plant as belonging to a genus 

 *' destitute of an external cuticle," which the plant I found evidently has. He 

 also describes his R. calcarea as having sessile fronds, " round, generally clus- 

 tered or aggregate, each as big as a pea, or larger, but often united into an 

 uneven undeterminate mass- The external surface is of a rich dark green." My 

 Palmella, on the contrary, is of a dark glue colour, not aggregated, oval, or he- 

 mispherical, and more than two inches in diameter. The Rivularia is also stated 

 to be " impregnated with a calcareous sediment, which renders it hard, though 

 friable," while certainly there was no trace of any stalagmitic particles in my 

 plant, which I believe to have been before unnoticed. 



Passing from the cavern to Curn Porth Farm, to obtain a draught of milk, I 

 noticed a singular old Elder-tree (Sambucus nigra), of larger dimensions than 

 any that ever previously came under my inspection. It had quite a venerable 

 aspect, hoary with Lichens, bearded with Polypody, and entirely hollow. Its 

 girth at the base was 14 feet, and 8 feet at two yards from the ground. I have 

 before hinted at the probability of the introduction of this tree into Britain by 

 the Romans, who long made South Wales a favourite seat of their arts and arms ; 

 and this singular old relic in the neighbourhood of an ancient Nidum, and not far 

 removed from a Roman way over the mountains, is in favour of my idea ; the 

 virtues and fame of the Elder having travelled hither from Greece, and been 

 acknowledged by learned compounders in all ages. Hence, even so late as 

 Evelyn's time, he has not scrupled in his Sylva to enlarge upon the " uses of 

 the Elder, either for sickness or wound." " The inner bark," he says, " applied 

 to any burning, takes out the fire immediately ; that, or, in season, the buds, 

 boiled in water-gruel for a breakfast, has effected wonders in a fever ; and the 



