1922] Fernald,—Polypoiudm virginianum and P. vulgare ` 135 
border), then from the Altai eastward across the Baikal region to 
Kamchatka. I have seen no Altai nor Japanese material and it is 
probable that all the Japanese plant is referable to P. Fauriei Christ, 
Bull. Herb. Boiss. iv. 672 (1896). (P. vulgare, var. japonicum Franchet 
& Savatier, Enum. Pl. Jap. ii. 244 (1879); P. japonicum (Franch. E Sav.) 
Maxon, Fern Bull. x. 42 (1902), not Hoult. (1783)). The plant of 
Amur and Manchuria, however, well shown in the Gray Herbarium, 
is neither European P. vulgare nor the Japanese P. Fauriei but is a 
good match in all characters for the eastern American P. virginianum. 
This specific identity of the Polypody of Amur and Manchuria 
with the plant of eastern America, while the western American species 
prove to be inseparable from the European, is so exactly what we 
have learned to expect, that in itself it is some indication that we are 
dealing with two distinct species; and the various characters already 
discussed lead inevitably to the conclusion that P. vulgare and P. 
virginianum are separated by many fundamental differences. 
Another point worthy of brief note is the comparative variability 
of the two. In Europe Polypodium vulgare is so exceedingly given to 
the production of varieties and sports that it, along with the European 
and western American Blechnum Spicant and Athyrium Filix-femina,' 
supplies a large proportion of the 1119 varieties of ferns recognized 
in the British Isles alone in Lowe’s British Ferns, and where Found. 
The fact that, to quote Druery, “This species has been very liberal 
2 
in *sports',"? supplemented by the infectious charm of the couplet, 
*How wonderfully you vary, 
Polypodium vulgare.” 
has stimulated the fern lovers of eastern America to emulate their 
British cousins in searching for these so-called varieties. The result 
is well stated by Waters in the words: “The common polypody 
lof eastern America, i. e. P. virginianum] is not ordinarily a variable 
fern."? How different from Druery’s statement just quoted or that 
of Mr. James Britten, in writing of the European plant: “The Poly- 
1 “in the eastern United States and Canada there are two distinct species of lady 
ferns, neither of which is conspecific with A. Filir-femina (L.) Roth of Europe 
the ferns of the northwest are conspecific with the European plant, but, in 
some cases, differ from the common European forms of A. Filix-femina in certain 
minor points’’—Butters, Ruopora, xix. 178, 179 (1917). 
? Druery, Brit. Ferns, 172 (1910). 
3 Waters, Ferns, 81 (1903). | 
