Aspidium remolum of A. Braun, a name adopted by Mettenius; 
but Braun afterwards considered it a variety of Jspidium (our 
Nepltr odium) rigidum of Swartz. Of this German plant I have 
received authentic, but cultivated specimens, through the kind¬ 
ness of Dr. Mettenius. Of the American native plant I have 
specimens also, from a valued correspondent, D. C. Eaton, Esq., 
of New York, and this is, I think, identical with our plant. 
The different views of botanists who have studied this Eern, 
prove how difficult it is to come to a satisfactory conclusion as to 
its specific identity, and yet nearly all agree as to its nearest 
affinities. I have already mentioned the changes of opinion in 
Braun, in now considering it a form of Aspidium rigidum* Pro¬ 
fessor Koch does not, that I can find anywhere, call it “ Polystichum 
remotum ” but says, under his Polystichum rigidum (Syn. El. Germ, 
ed. 2. p. 979), that it is perhaps rather to be considered as a 
very vigorous and submuticous state of Aspid. spinulosum, than 
as referable to rigidum. Mr. Moore, though preserving it as a 
species, says that “ its structure agrees more closely with that of 
Filix-mas than with spinulosum or rigidum Mr. Clowes, in the 
f Phytologist/ above quoted, has some very interesting remarks 
on the affinities of this plant (which he has cultivated for several 
years), but which are too long to be here introduced in extenso. 
Both Mr. Huddart and himself (and it would seem it was de¬ 
tected by them in concert) considered it a luxuriant specimen of 
Lastrea crista/a, var. sjnnulosci , “ but in the garden it gradually 
became more like Filix-mas , indeed it was found growing with 
Filix-mas , var. incisa , and abbreviata, with L. spinulosa and L. 
dilatata, and about five miles from Limestone Rocks, where L. 
rigida is abundant /’ and he concludes, “ as this Eern appears to 
connect the two forms L. spinulosa and Filix-mas , we have now, 
it would seem, a continuous series from typical Filix-mas to L. 
dilatata , as the latter and spinulosa are apparently united by 
glandulosa .” 
The American botanists have experienced the same difficulty 
on this subject with their plant. Not having access probably 
to the German authors, it was considered by Mr. Tuckerman a 
new species, which he described under the name of its dis¬ 
coverer in the United States, Aspid. Boottii. Dr. Asa Gray, 
in the first edition of his ‘Elora of the Northern United States/ 
looked upon it to be a luxuriant form of Aspid. rigidum , Sw., 
yet allied to spinulosum. In his second edition of that valuable 
Elora, he makes it var. Boottii of Aspidium spinulosum , Sw.; 
“ the least dissected form, intermediate in appearance between 
* Mr. Moore indeed says, “ it appears from specimens lately received from 
Braun, that he now considers it a variety of Aspidium Filix-mas.” 
