.80 Bolton's woodsia. 



Acrosticlium alpinum, Bolt. Fil. Brit. 76, t. 43. 



Acrostichum liyperboreum, Liljehlad, St. Tr. 201, t. 8. 



Woodsia hyperborea, B. Br. Tr. Linn. Soc. xi. 173 ; Sm. E. 

 F. iv. 323, ?E. B. 2033 ; Hook, and Am. 567. 



Woodsia alpina, Neivm. N. A. 13, F. 143, Phyt. App. xxvii. 



This little fern is excellently represented by Bolton, whose 

 figure is so like my own that I thought it quite unnecessary to 

 copy it, otherwise I should have done so, with a view of con- 

 firming the specific name ; also by Bauer (in illustration of Dr. 

 Robert Brown's paper in the Linnean ' Transactions '), and by 

 several continental authors. 



With regard to the specific name, I have proposed a change 

 which may, at first sight, apj)ear to be somewhat capricious, but 

 which, when investigated, will, I trust, be found in accordance 

 with the received principles of botanical nomenclature. The 

 specific name of " hyperborea " has been applied to this plant 

 by Liljeblad, Swartz, Willdenow, Brown, Wahlenberg, Smith, 

 Hooker, and many other botanists ; indeed, it seems so sanc- 

 tioned by authority, that it is not without great reluctance that 

 I venture on the alteration which I will now attempt to justi- 

 fy. The first description of this fern that I can find is that in 

 Bolton's ' Filices ; ' it is under the name of Acrostichum alpi- 

 num, and is as follows : — -"The root of this little Acrostichum 

 consists of a few black, hard branches, connected to a small 

 head, and furnished with black, hard, capillary fibres. The 

 rib of the first leaf, when fuU grown, is about three inches high, 

 of a pale brownish green colour, slender, and smooth, being 

 quite destitute of hairs. Second leaves six or seven pairs, op- 

 posite below, alternate above, of a triangular figure, obtuse at 

 the corners of three or four of the lower pairs, but all of equal 

 size and remote, two or three of the upper gradually lessening 

 and growing closer together. Lobes of the second leaves most 

 commonly five, two on each side of the rib and one at the end ; 

 they are of a roundish figure, grow close together, and are ob- 

 scurely crenated round the margin. The colour on the upper 

 side is a brownish kind of green ; the under side thickly covered 

 with a brown hairy nap. The lower figure represents one of 

 the second leaves as it appeared when a little magnified : the 

 seed-vessels are disposed in three or four clusters on each lobe, 

 partly hidden among the numerous strong brown hairy filaments, 



