Juke 1903.] BOTANICAL SOCIETY OF EDINBURGH 315 



Iq concluding, I should like to refer briefly to the 

 points which distinguish from one another the three 

 British species of shield-ferns, viz. P. Lonchitis, P. acideatum, 

 and P. aiKjulare. 



It will no doubt surprise some that we do not here 

 include lohatum, especially as it is a name used both in 

 an aggregate and in a segregate sense in the " London 

 Catalogue of British Plants." Opposite views are held 

 as to whether we have two distinct plants in lohatum 

 and acideatum. The balance of opinion seems to be with 

 those who consider that we have but one, viz. acideatum, 

 and that what has been known as lobatuni is but an early 

 or immature state of the former, with the fronds more 

 lanceolate and rigid, and with pinnules confluent and 

 decurrent, or that at best it is but a variety of acideatum. 

 Newman, in his "History of British Ferns," Ed. 3, p. 112, 

 published in 1854, gives it as his opinion — (1) That the 

 dividing of the bipinnate aculeate ferns into three species — 

 lobatum, acideatum, and angulare — probably originated in 

 an error of nomenclature, due to the various independent 

 namings of Liunseus, Hudson, Kiintze, Willdenow, and 

 Sir J. E. Smith ; (2) that the three names, lohatum, 

 aculeatum, and angidare, were not intended to represent 

 three objects ; and (3) that there was a disposition to 

 reunite them as one species. Thomas Moore, in referring 

 to this in his " Nature-printed British Ferns," published in 

 1859, says: "It is doubtful if Linnasus knew anything of 

 angulare, though there is hardly any room to doubt that 

 he included the other two under acideatum." This, Moore 

 says, is the view which he himself and Newman had botli 

 adopted. 



One or two more recent opinions on this matter may 

 also be mentioned. 1. We find Mr. F. Arnold Lees, 

 perhaps the best botanist in the north of England, re- 

 marking as follows in his " Flora of West Yorkshire," 

 published in 1888: — "The form lohatum of Smith is 

 frequent wherever the type occurs, but is not a true 

 variety." 2. Mr. Chiirles T. Druery, to whom I have 

 submitted a considerable series of what might be supposed 

 to include examples of both lohatum and aculeatum, replied: 

 " I do not consider there is any real distinction between 



