Blechnum filiforme

This one had me wondering what it was for some time. Then I discovered it has three forms, and this image is of the juvenile form.

It is the only climbing Blechnum, and spreads by rhizomes (an underground stem).

When the spreading rhizomes reach a tree trunk, they will climb up and the fronds can eventually completely cover the tree.

In the adult form the fronds are much larger, with the pinnae ("leaves") becoming longer and tapered.

The fertile fronds form only on the climbing rhizomes, and can be quite high up. They have very long thin pinnae.

This image shows the adult form with both sterile and fertile fronds. This part of the fern was growing at the top of an old tree brought down in a storm, and I was lucky enough to spot it dangling amongst the broken branches.

Common names of the fern are: Climbing hard fern and Thread Fern


fern index