IS 
European Ferns. 
occupy the same position as in the last species ; next the rachis they are more conspicuous 
than those of H. tunbridgense ; the valves or segments are ovate, and their margins are quite 
entire. The habit of H. Wilsoni is more erect ; it affects somewhat different situations, and 
often occurs on bleak and exposed rocks. 
In geographical range it is a more northern plant than H. tunbridgense , but the two 
species are sometimes found growing intermixed. In England it is recorded for Cornwall 
and Devon, Stafford, Salop, and most of the Welsh counties, Lancashire, Yorkshire, and the 
northern counties ; it is pretty generally distributed through Scotland, finding its north limit 
in the Orkney and Shetland Isles. In Ireland it is much more frequent than the last, occurring 
in hilly districts in all parts of the country. Its Continental distribution is much more restricted 
than that of H. tunbridgense , the Faroe Islands and Norway being the only extra-British 
localities in Europe for the plant. Beyond the continent of Europe, however, it is recorded by 
different writers under different names from South Africa, the island of Bourbon, Madeira, and 
the Azores, the Fiji group, New Zealand and Australia, Chili, Guatemala, the Andes of Peru, 
and Brazil. Like the last it is absent from Asia. 
The plant is more generally known under the name of H. unilaterale , Bory. Its name, 
Wilsoni, was given it by the late Sir William J. Hooker, in compliment to the late William 
Wilson, of Warrington, an assiduous British botanist, who added several species to the British 
flora, and whose “ Bryologia Britannica” will long remain the standard work upon British 
mosses. Pie died in 1871, and his unequalled collection of mosses now forms part of the 
treasures of the Botanical Department of the British Museum. 
In the Supplement to “English Botany” (Tab. 2686), the 
plant is figured and described by Mr. Wilson, who says : 
“ So very different in aspect is this truly distinct species from 
the far more elegant H. tunbridgense, that no botanist who has 
had the good fortune to see them luxuriantly growing in com- 
pany in the rocky woods which border the wildly-sequestered 
Upper Lake of Killarney, would hesitate to pronounce them 
two species. It was there that, in the summer of 1829, I first 
became acquainted with the true II. tunbridgense, and had at 
once the gratification of clearing up any doubts concerning 
the spurious kind, with which, as the common Hymenophyllum 
of North Wales, Cumberland, and Perthshire, I had long been 
imperfectly familiar, and also of unexpectedly adding another 
fern to the British flora. Hudson, who probably had seen and 
gathered both kinds, does not notice this species as a variety ; 
but various botanists of modern times have suspected, though 
they did not ascertain nor promulgate, the existence of two British species. ... So 
constantly has this species been confounded with II. tunbridgense, that it is perhaps impos- 
sible to fix any certain reference to the works of Ray, or of any later author : it appears 
also to have been wholly unobserved on the Continent.” 
IIYMENOrHYLLUM WILSONI. 
