THE ALPINE POLYPODY. 88 
fructification, some indication of being a monstrous or abnormal 
variation, though it is perfectly constant to the peculiarities above 
assigned to it. It differs from P. alpestre in being more slender and 
flaccid; in having a much narrower outline, and consequently shorter 
pine, with a considerably reduced number of pinnules ; in the form 
of the pinnules, which are oblong, narrowed below, sessile or adnate, 
and distantly toothed ; in the very short stipes which becomes obso- 
lete in the cultivated plants; and in a tendency to bear perfect sori 
at the base of the frond, while the apex is barren—the reverse of 
what usually happens. The fronds are from six or seven to twelve 
or eighteen inches in length ; the pinnæ, spreading or more or less 
deflexed, short, with about six or eight pairs of pinnules. The sori 
are. few, six or eight on a pinnule, usually distinct; in the cultivated 
plant the clusters are very numerous in the lower half, and scarcely 
extend upwards beyond the middle of the frond; but this character 
is not constant, the fronds being sometimes fructified throughout, 
and sometimes fertile both at the base and apex. The spore-cases 
sometimes appear for the most part to be attached to the side of the 
vein, and the sori slightly elongated rather than circular, indicating 
an affinity with Athyrium; and there is in some cases a peculiar 
membranaceo-filamentous development in the position of an indu- 
sium, again indicating affinity with the ciliated indusia of Athyrium ; 
but at the base and apex of the frond, the more perfect sori are 
generally without trace of this indusioid growth, and. truly polypo- 
dioid. The absence of stipes, which Mr. Newman includes in his 
definition, is not constant, the wild specimens sent by Mr. Backhouse 
having a distinct stipes about a couple of inches long ; this part, 
however, is always short. It is certainly a very distinct variety, 
and very constant, probably a variety rather than a species, this, 
moreover, being the view adopted by its discoverer, Mr. Backhouse, 
who writes :—“ Dissimilar as it is from P. alpestre, I shall continue 
doubtful of its specific difference if it does not turn up in other 
places.” Mr. Backhouse, by whose party only it has been found 
wild, met with it in one place only, but in some quantity, in Glen 
Prosen, Clova, Forfarshire. 
2. lanceum (M.). In this the fronds are large, stout, subtripinnate ; 
the pinnules elongate, ovato-lanceolate or sometimes sublinear, 
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