214 THE BLADDER FERNS. 
Cystopterits bulbifera ranges trom Canada to Tennessee, 
Arkansas and Wisconsin and is also reported from 
Alaska. It is rather irregularly distributed, being very 
common in some localities and entirely absent from 
others that seem equally favourable to its growth. It is 
found on many rocks other than limestone and is excel- 
lent for the rockery in the fern garden. This species 
shares with the maidenhair the honour of being first to be 
sent to the Old World by botanical explorers. In Great 
Britain it is occasionally known as the berry-bearing 
fern. 
The Mountain Bladder Fern. 
The mountain bladder fern (Cystopterts montana) is not 
likely to be found by the eastern collector. Itis a 
rare species within our limits, coming south only as far 
as Labrador and Northern Canada. It has also been 
found north of Lake Superior and in the mountains of 
Colorado. In Northern Europe and Asia it is rather 
more abundant. It may be distinguished from the 
other bladder ferns by its almost triangular fronds on 
long straw-coloured stipes. It is usually about a foot 
high and grows along woodland streams in deep shade. 
The blade is thin, three to four times pinnate, the pinne 
much like the frond in shape. The pinnules are deeply 
toothed and the soriabundant. The indusium is pointed 
at the free end, and soon withers. Our illustration is 
from a plant, rather smaller than ordinary, collected in 
the Cape Nome gold fields. 
