1917] Butters,— Studies in Ferns — Athyrium 187 
The next stage in the treatment of the North American lady ferns, 
is that represented by the work of W. J. Hooker, Asa Gray and D. C. 
Eaton. Hooker at first ! reduced all the lady ferns of British North 
America, eastern and western, to Athyrium Filix femina with variety 8 
(Aspidium angustum Willd.) and var. y of the northwest coast. In 
both the typical species and his var. 8 he included western as well as 
eastern forms. He later? transferred the species to Asplenium, and 
discarded all varieties. In his Species Filicum he says, “I do not 
find any of the N. American forms to differ essentially from the 
European.” 
American authors since Hooker’s time have generally followed 
him pretty closely. Thus in the first four editions of Gray’s Manual 
1848-1863) we find beneath the description of “ A[splenium] Filiz- 
foemina,” the following explanation: “(Aspidiwm Filiz-foemina and 
asplenioides Swartz.) — A narrow form is Aspid. angustum, Willd. 
Moist woods, common. July.” In the fifth edition (1869) the con- 
cluding sentence is changed to “ moist woods, common and very vari- 
able. July. (Eu.)”, while in the sixth edition (1890, Watson and 
Coulter), the synonymy disappears entirely, and the description 
is followed merely by the statement, “Moist woods; common, and 
presenting many variable forms. July. (Eu.).” The only change in 
the seventh edition (1908, Robinson and Fernald) is the substitution 
of the word “cosmop.” for “Eu.”’. 
Likewise in the earlier editions of Wood’s Class Book, under 
“Alsplenium] Filix-foemina Bernh.” are cited the synonyms, “ Aspi- 
dium Filix-foemina and asplenoides [sic] Sw. A. angustum W.”, but 
beginning in 1861, these names disappear even as synonyms. D.C. 
Eaton * reduces all North American lady ferns to “ Asplenium Filix- 
foemina.” He says, “The so-called varieties of this fern are almost 
innumerable, but all pass into one another by various gradations. 
The chief forms occurring in North America are the following.” He 
then enumerates and describes vars. exile, angustum, latifolium, 
commune and cyclosorum. His chief illustration (pl. 76, no. 1) is 
drawn from a specimen of Athyrium asplenioides. 
European botanists have generally kept the east American ferns as 
species distinct from Athyrium Filix-femina, the most notable excep- 
1 Hooker, W. J., Flor. Bor.-Am. ii. 262 (1840). 
2? Id. Species Fil. iii. 219 (1860). 
3 Eaton, D. C., Ferns of N. A. ii. 225 (1880). 
