24 
BRITISH FERNS. 
is a handsome species, growing to the height of feet. 
It increases rapidly by means of its creeping caudex, 
dies down in winter and reappears the following spring 
more luxuriant than ever. It is perfectly hardy, and 
very pretty, especially the variety with purple stems. 
It is a native of North America. 
Cystopteris bulbifera. Bulb-bearing Bladder-fern . 
Fronds bipinnate, lanceolate, nearly erect, tapering 
elegantly to the apex, about a foot high, and bearing 
towards the top numerous little bulbs, about the size of 
a pea, which fall off or are easily detached, and repro- 
duce the plant. It is a native of North America, Ca- 
nada, and the United States. 
Cystopteris sempervirens . Evergreen Bladder-fern . 
Closely resembling Cystopteris fragilis, and considered * 
by Mr. Moore only an evergreen variety of that species. 
Blechnum alpinum . Alpine Hard-fern . Barren fronds 
lance-shaped, erect, pinnate, bright green, 4 inches high ; 
pinnae oblong, rounded margins entire. Fertile fronds 
contracted, pinnate, 6 inches high ; pinnae far apart. 
Caudex creeping. This fern requires its roots protecting 
in winter either by a covering of dead leaves or by a 
hand-glass. It increases rapidly by means of its creep- 
ing caudex, and is a pretty dwarf species. It is a native 
of the hills of Tasmania. 
Blechnum crenulata . Notched Hard-fern . Caudex 
tufted ; fronds narrow, lanceolate, pinnate ; pinnae 
pointed; fertile fronds about 6 inches high; barren 
ones about 5 inches, all growing together in a dense 
tuft; stems reddish. Introduced from Chili by Mr. 
Yeitch. 
Scolopendrium vulgar e, var. undulatum . Waved Hart’s- 
tongue. A beautiful and w ; ell -known variety, with the 
