CYSTOPTERIS ANGUSTATA. 105 
CYSTOTTEKIS ANGUSTA'TA. 
THIS has various English names, and among botanists, 
with still more varied want of certainty, has been placed 
in various genera, or been reduced even to a mere 
variety. 
It is known as the Deep-cut Mountain Bladder Fern, 
as the Stone Polypody, as the Red-stemmed Polypody, 
and in botanical works it is Polypodium rhaticum, Poly- 
podium ilvense, Aspidium fragile, Aspidium rhaticum, 
Cyathea fragilis, var. ft. and Cystopteris fragilis, var. 
angustata. 
We think that it has sufficiently distinctive cha- 
racteristics to retain it as a species. Moot tufted, some- 
what creeping, black, with rusty scales, and rootlets long. 
Fronds from six to fifteen inches high, rather numerous, 
erect ; stalk dark-red becoming black, nearly half its 
length naked, without any border, slender, and smooth. 
Leaflets bright green, nearly opposite, the lowermost 
rather shorter, and the pairs at greater distances from 
each other than those about the middle of the frond, all 
leafited with scarcely a border down the side of the 
midrib. Leafits alternate, spear-head shaped, rather 
bluntly pointed, sometimes, however, tapering at the 
end, all deeply cut, with oblong wavy, pointed segments; 
and the ribs of all somewhat wavy. The segments are 
always long and narrow, never broad, rounded, or egg- 
shaped, but sometimes, though rarely, cloven at the end. 
The leafits on the upper side of each leaflet are larger 
