302 i\Ir. T. Moore on Lastrea uliarinosa. 



s' 



venieut season, it has been fortunate enough to obtain consider- 

 ation. For these evidences I sliall merely quote Newman, who 

 writing some years since of L. spinulosa, remai'ks : " it occurs 

 frequently in marshes, and there mingling with cristata, so 

 closely approaches it in appearance, that I have found the 

 greatest difficulty in separating them ;" the puzzling form al- 

 luded to being now identified by him as Lloyd's fern (Phytol. 

 iii. 679). As this intermediate form is found widely distributed 

 in England, occurring in Cheshire, in Nottinghamshire and in 

 Norfolk, I assume that it probably exists also in Sweden, and if 

 so, may have formed the stumbling-block of Linn?eus in his idea 

 of the species " cristata," and in some measure justified him in 

 uniting, or "confounding" as it is said, if he really did intend 

 to unite, the ferns which we moderns call Lastrea cristata and 

 ^inulosa. 



As to whether Lloyd's fern is specifically distinct, different opi- 

 nions will be held, no doubt. From the first it has appeared to 

 me as being intermediate between the two species just named ; 

 but before having seen the barren fronds, which the plant I be- 

 lieve constantly produces, I was led to think it more closely 

 allied to spinulosa than to cristata. I\Ir. Lloyd himself thinks it 

 intermediate between these two kinds ; and Mr. Newman calls 

 it " almost precisely intermediate," which, in I'act, it is. Its re- 

 lationship thus seems clear enough ; but I do not agree in the 

 conclusion which has been drawn, namely, that being thus inter- 

 mediate, it cannot be referred to either species as a variety, and 

 must either combine them into one, or itself be regarded as a 

 species. 



Lastrea uliginosa is correctly said to differ from each one of its 

 allies, in certain points in which it resembles the other. Thus 

 the " more acuminate, more di\'ided, more serrated, more aristate 

 pinnules," which separate it from cristata, unite it to spinulosa ; 

 and the " adnate decurrent pinnules," together with the outline 

 of the barren fronds which separate it from spinulosa, unite it to 

 a-istata. The " erect rigid habit," the " obovate diaphanous con- 

 colorous scales," and the " entire eglandulous " indusium, are 

 characters common to both ; and it differs from both, as we are 

 told, 07ily in the " more equal distribution of the clusters of cap- 

 sules over all parts of the frond." This latter is however an un- 

 sound character, for I have gathered specimens, undoubtedly 

 L. spinulosa, in which every pinna is as thoroughly furnished 

 with perfect sori, as is the case in Lloyd's fern. 



It thus appears that no tangible specific character has been 

 pointed out by which to distinguish L. uliginosa (Newm.) as a 

 species. I do not however fall back upon the alternative already 

 mentioned — that of uniting cristata and spinulosa — though it is 



