Pol ypodium . 
169 
is occasionally divided ; but this is an abnormality common to most ferns, and no form of the 
species has been considered worthy of a name. 
POLYPODIUM ALPESTRE, Hoppe. 
This is a species regarding which different views have been taken, the result of which is 
that it has been placed in various genera. Different authors have regarded it as a Polypodium, 
an Aspidium, and an Athyrium ; and Mr. Newman regarded it as the type of a distinct 
genus, which he called Pseudathyrium. We follow Mr. Moore in placing it in Polypodium. 
roi.vroDiuM ai.pestrf. (reduced). 
Besides the various generic names, its specific one varies, it being often referred to as 
Polypodimu rhceticum , under which name we have included it in our preliminary list 
(Introduction, p. xvii.). 
Although considered as a Polypodium by the best authorities, it must be admitted that this 
fern has little resemblance in appearance to the other members of that genus. It is, indeed, 
far more like the Lady Fern {Athyrium Filix-fcemina) ; so much so, indeed, as to be frequently 
confounded with it. The short thick tufted caudex and the general form and style of the 
fronds remind one at once of Athyrium or Lastrea ; but the fruit usually at once distinguishes 
it from either of those genera. Those who have regarded it as a Lastrea or as a separate 
genus have done so on account of the indusium which they supposed to exist. On this point 
it may be well to extract what Mr. Moore has said : “ The supposed ‘ indusia ’ ascribed 
to this plant, which may be noticed both in the species itself, and in the variety flexile , are 
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