509 



On the identity of Nephrodium faenisecii, var. alatum, of Madeira, 

 with Lastnea recurva of Britain. By Edward Newman. 



The Nephrodium fcenisecii of Mr. Lowe, like the Polypodium cris- 

 tatum of Linnaeus, the Aspidium dilatatum of Smith and the Aspidium 

 spinulosum of Hooker, comprises that little group of species belong- 

 ing to the genus Lastraea, the ultimate divisions of whose pinnge are 

 aristate or spinulose. It is, in fact, the Madeira representative of this 

 little group. I will not here anticipate the conclusions of a paper 

 long since written but still unpublished, on the exact nature of simi- 

 larities existing between plants of distant countries, but merely say 

 that little group in question has been called cristatum in Sweden, di- 

 latatum or spinulosum in Britain and fcenisecii in Madeira : it abounds 

 in other parts of the world, particularly North America, where it still 

 remains to be divided, the various names at present in use applying 

 equally to all the species. 



Mr. Lowe has, however, done more than Linneus or Smith (neither 

 of whom indicate the existence of other species, by the mention of va- 

 rieties) ; for he expressly describes two varieties under the names of 

 a. alatum and &. productum, and I am indebted to Mr. Watson for 

 calling my attention to the fact that the variety alatum possesses all 

 the characters of our British Lastraea recurva ; and a sight of Mr. 

 Watson's specimens, which he has most kindly placed before me, has 

 fully convinced me of the correctness of his views. It is, however, a 

 fact worthy of remark, that Mr. Lowe has not made the slightest allu- 

 sion to either of the three characters which immediately distinguish 

 recurva from any other aristate Lastraea, although these characters are 

 possessed by the Madeira specimens in a very pronounced matter : I 

 allude to the minute, sessile, grain-like glands scattered over both sur- 

 faces of the frond : the jagged, eglandulose involucre : and the long, 

 slender and laciniated scales of the stipes. Mr. Lowe's description 

 is principally confined to the figure and cutting of the frond, charac- 

 ters which till lately obtained the exclusive attention of our botanists. 



The var. B. productum is less distinctly marked, and may be sup- 

 posed to contain the remainder of the aristate group. Among the 

 specimens thus named, Lastraea multiflora occurs in a very pronounced 

 state. 



Mr. Lowe's descriptions are published in the fourth volume of the 

 * Cambridge Philosophical Transactions,' at page 7, and were read 

 in 1830. They are reprinted verbatim below. 



Vol. II. 3 r 



