Blechnum. 
67 
implies, illustrating our remarks by reference to the repeatedly unsuccessful attempts to induce 
any kind of tree to grow in Manchester Cathedral-yard. Londoners who are accustomed to 
see plane-trees flourishing in the heart of the city, and who find it possible to maintain 
a very decent semblance of a garden round St. Paul’s itself, would look with astonishment 
on the few black sticks which are all that remain of the last attempt at tree-planting in 
Manchester. The fearfully vitiated atmosphere of course explains the whole matter, but tree- 
planting is not always a success even under more favourable auspices ; what, for example, 
could be more melancholy than the attempts at arboriculture which we may suppose were 
intended to adorn the pavements in Sackville Street, Dublin ? 
But we must now pass on to the genus Blechnum , a genus containing some twenty or 
thirty species — although this estimate varies, some plants referred to it by certain authors being 
considered by others as belonging to Lomaria — bearing for the most part a general resemblance 
one to the other, and widely distributed through the tropical and south temperate regions 
of the globe. Our sole European representative, B. Spicant , which we shall shortly consider 
more at length, is a plant of wide distribution, but the other species are more restricted in 
their range, but few of them being common to both hemispheres. One tropical American 
species, B. volubile, is, as its specific name denotes, of climbing habit. It has a spreading, 
twining stem, by which it climbs to the top of lofty trees to a height of from twenty to 
thirty feet, and bipinnate fronds; some peculiarity in the indusium induced Mr. John Smith 
to propose this as the type of a new genus, Salpichlama , but it is now generally con- 
sidered as a species of Blechnum, remarkable on account of its scandent mode of growth. In 
this it bears a strong resemblance to Lomaria volubilis, to which we have already referred. The 
pinnules vary a good deal in length and breadth, but are often very large ; they are some- 
times as much as fifteen or sixteen inches long, and (the barren ones) two inches and a half 
broad. Mr. Purdie, who collected the plant 
in Columbia, has recorded that when the sori 
and involucres have completely fallen away 
from the fertile pinnules, the last-named, which 
have hitherto been narrower than the barren 
ones, increase in size until they are indis- 
tinguishable from these latter. 
Among the exotic species of Blechnum 
which are — or have been— in cultivation in 
England, none is more distinct than B. Lanceola , 
a small evergreen species, native of Tropical 
America from Panama southwards to Brazil 
and Peru. This, indeed, cannot be confused 
with any other species of the genus, being 
distinguished from all of them by its simple 
fronds. These are from four to six inches 
long, and usually less than half an inch 
broad, narrowed gradually at each extremity, 
and rising on slender stipites from a creeping stoloniferous rhizome ; the sori form a con- 
tinuous line close to the midrib. This was in cultivation in Kew in 1841, and is not 
very uncommon in collections, although its interest lies rather in its exceptional appear- 
