Blechnum cartilagineum is attractive and very hardy. It grows
in open forested areas and in some surprisingly dry areas in the dry
sclerophyl eucalypt bushland. The sterile and fertile fronds have the
same form and size, typically 20cm (8") across and up to a metre
tall when fully mature. A key characteristic is the variable angle between
pinna and rhachis from the initial pinnae to the frond tip. At the stipe
end it starts at around 45° backwards, progresses through 90°
and finishes up around 45° forwards. This picture is of several
young fronds and shows the trait. The illustration in Jones and Clemesha's
Australian Ferns and Fern Allies does not show this behaviour,
but in all examples in this region it seems to occur.
This
image shows the length of the pinnae on B. cartilagineum, which
is much greater, relative to the frond size, than other members of the
Water Fern family.
A close up of a frond tip showing slightly sickle-shaped alternating
pinnae.
Blechnum cartilagineum is attractive and very hardy. It grows
in open forested areas and in some surprisingly dry areas in the dry
sclerophyl eucalypt bushland. The sterile and fertile fronds have the
same form and size, typically 20cm (8") across and up to a metre
tall when fully mature. A key characteristic is the variable angle between
pinna and rhachis from the initial pinnae to the frond tip. At the stipe
end it starts at around 45° backwards, progresses through 90°
and finishes up around 45° forwards. This picture is of several
young fronds and shows the trait. The illustration in Jones and Clemesha's
Australian Ferns and Fern Allies does not show this behaviour,
but in all examples in this region it seems to occur. 
This
image shows the length of the pinnae on B. cartilagineum, which
is much greater, relative to the frond size, than other members of the
Water Fern family. 
