BLACK SPLEENWORT. 
559 
and appears to me exactly intermediate between the two others. 
It is the Adiantum nigrum ojfficinarum, Common black Maiden- 
hair or Oak fern, of Ray’s ‘ Synopsis.’ Sadler makes its distin- 
guishing character to consist in the stem being not winged.^ 
AspleniumAdiantum-nigrum^\dx.acutum. (See. fig. c, p. 257). 
Asplenium acutmn, Bory. 
Sprengel, Willdenow and Sadler, all of them give an Asple- 
nium a utmn, which I think must be identical with Ray’s Filix 
minor longifolia^-\ described from specimens found on the moun- 
tains of Mourn, in the county of Down, in Ireland. Dillenius, 
the editor of the edition of Ray’s ‘ Synopsis ’ from which my 
quotations are made, expresses a doubt as to its distinctness as 
a species, since no fructification had been observed, and suggests 
the possibility of its being a variety of Adiantum-nigrum, in- 
debted for its peculiarities to the fact of its growing in a cave into 
which the solar rays could not enter.J Smith, who makes it his 
var. /3. of Adiantum-nigrum, informs us that Sherard’s original 
specimen is preserved in the herbarium at Oxford, that it is truly 
elegant, of a delicate membranous texture, the leaflets palmate 
and finely laciniated, and that no fructification is discernible. § 
Mr. Wilson and Mr. Mackay have found this variety at Killarney. 
“ I found,” says Mr. Mackay, ‘‘in 1805, on the limestone rocks at 
Mucruss, a beautiful and delicate variety [of Adiantum-nigrimi]^ 
with fronds tripinnate throughout, or with pinnules deeply and 
finely laciniated ; it was subsequently found by Miss Hutchins 
and Dr. Taylor, and Mr. W. Andrews lately gave me a specimen 
collected by him, in 1835, on a mountain called Cahir Conree, 
six miles from Tralee.” |1 I am indebted to Miss Carpenter, of 
Bristol, for an opportunity of seeing and carefully examining a 
specimen gathered near Cork ; the lowest pinna of the frond is 
* Rhaclii non alata. — De Filicibus Veris, &c., p. 31. 
f Filix minor longifolia tarsis raris, pinnulis longis tenuissimis et oblongis, 
laciniis fimbriatis D. Sherard. — Syn. 127. 
t In hac planta seminalia nulla observare contigit unde an species vere dis- 
tincta sit, dubium videtur. Forsitan non nisi varietas est Adianti nigri offici- 
narum J. B. loci ombrositati originem debens, nam in spelunca, quain radii 
solares nunquam illustrabant, nascebatur. Sane vero si varietas sit, singularis 
ea est et valde speciosa. — 1. c. 
§ Eng. FI or. iv, 298. 
H Flov. Hibeni. 342, 
