46 The Scottish Naturalist. 



The second question I proposed was, " What value is to be 

 placed on these characters ? " To answer that we must see 

 what points of distinction are considered of specific value in 

 other ferns. Let us take, for example, Polystichiun aculeatum and 

 lobatuui, which latter Hooker makes a subspecies, though Babing- 

 ton considers it to be only a slight variety. The characters 

 on which Hooker assigns subspecific rank to lobatum are, that 

 the pinnules are more rigid, and decurrent and confluent below. 

 Angulare he also considers a subspecies of aculeatum, differing 

 by its softer and more membranous texture, laxer and smaller 

 pinnules which are stalked. It must be remembered that there 

 is a host of varieties connecting, in a greater or less degree, all 

 these subspecies, but more especially the two first mentioned. Or 

 we may take the two British Woodsias — hyperborea and ilvensis ; 

 the latter differing from the former, according to Hooker, by 

 being more erect and scaly, and with narrower and more deeply 

 divided pinnae. 



If, then, such characters are considered sufficient in Woodsia 

 and Polystichum to constitute species or subspecies, surely they 

 ought to suffice to raise flexile to a higher rank than that of a 

 mere variety of alpestre. There may be intermediate forms 

 connecting alpestre and flexile, but if such there be, I have not 

 been able to find any mention of them ; and Newman, in first 

 describing flexile, says expressly that amongst a large series no 

 varieties were observed, "or any form that would indicate an 

 approach to described species." Judging, however, from New- 

 man's figures and descriptions, and Hooker's and Babington's de- 

 scriptions, the Glen Prosen plant, which is the only one seen by 

 Newman and Babington, and perhaps also by Hooker, does differ 

 a little from the plants on the table to-night, which are from 

 Ben Aulder, more especially in having both pinnae and pinnules 

 more distant. I have unfortunately no specimens to compare ; 

 but if I remember aright, a plant from Glen Prosen, which I saw 

 some years ago. had the characters depicted by Newman. If 

 this be the case these plants show no approach to alpestre, but 

 on the contrary a greater divergence. Flexile is also reported 

 to have been found in Sutherlandshire, but of this report I 

 know nothing ; nor do I know of any record of it having been 

 met with out of Scotland, though I see that Babington refers 

 with a query the Polypodium rhazticum of the Flora Danica to 

 flexile. Grenier and Godron, on the other hand, consider the 

 rhaticum of Linnaeus to be the same as alpestre of Hoppe. 



