1917] Butters,— Studies in Ferns — Athyrium 185 
and foreign, is interesting and somewhat illuminating. Prior to the 
work of Michaux, no mention is made of the American occurrence of 
any species of this group. Michaux assigns two species to eastern 
North America, describing one as “ Nephrodium Filix foemina,” with 
the habitat “Canada,” and the other as “ Nephrodium asplenioides,” 
with the habitat “from New England to Carolina.” ! 
The following year, Sprengel ? described Asplenium Athyrium appar- 
ently from slightly different material of the same species which 
Michaux had called Nephrodium asplenioides. He states that he gives 
it this name because it has the greatest similarity to Athyrium Filiz- 
femina, and ends his description, “Ich vermuthe dass dies Michaux 
Nephrodium asplenioides ist.” These two names have been treated 
as synonyms by all subsequent botanists. In 1809, Schkuhr,’ after 
publishing a description of Asplenium Athyrium, with an excellent 
plate, had a change of heart and added the statement “aber nach 
andern Beobachtungen an mehrern aus Amerika erhaltenen Exem- 
plaren kann ich solchen jetzt von Aspid. Filia fem. nicht unterscheiden; 
selbst an unserer deutschen Pflanze dieses weiblichen Farn habe ich 
noch weit grössere Abinderungen gefunden, die von einigen als 
verschiedene Arten betrachtet werden.” 
In 1810 Willdenow t adopted Michaux’s species, treating it as Aspi- 
dium asplenioides, and citing as synonyms both the Nephrodiwm 
asplenioides of Michaux and the Asplenium Athyrium of Sprengel. 
He says of it, “A sequenti [A. Filix-femina] praeter forman frondis 
parum diversum, soris lunatis abunde distinctum.” He introduces a 
change into the description, saying, “pinnulis lineari-lanceolatis 
inciso-dentatis,” a change which is certainly not in the direction of 
greater accuracy, and which seems to have lead to considerable con- 
fusion. Willdenow gives the habitat of “ Aspidium Filix femina” as 
1 Michaux, Fl. Bor.-Am. ii. 268 (1803). The original description reads: [Nephrodium] 
ASPLENIOIDES. N. majusculum, glabrum: stipite nudo: fronde bipinnata; pinnulis subovali- 
oblongis, inciso-dentatis; dentibus inferioribus obtusis, supremis mutice acutis: punctis utrin- 
que juxta nervum lunatis. ; 
Obs. Affine Poryr Filici foem. et forsan varietas. Puncta maturitatem quasi lineolae 
plerumque arcuatae; .ita ut proximitatem as ASPLENIUM indigitent. 
HAB. a Nova Anglia ad Carolinam. 
This description and the range given apply distinctly to the more northern of our two east- 
ern species. A fragment in the herbarium of the New York Botanical Garden, consisting of 
two pinnules labelled “from Herb. Michx. Poly. asplenioides a Nova Anglia ad Carolinam ” 
confirms this application of Michaux’s name. 
2 Sprengel, K., Anleit. zur Kent. der Gew. iii. 113 (1804). 
3 Schkuhr, Ch., Kryptogamische Gewächse, 72 (1809). 
4 Willdenow, C. L., Sp. Pl. v. 276 (1810). 
