Blechnums: Hard and Soft Water Fern’s

Another post in our series for people wanting to know more about the fern species in Tarra Bulga National Park and how to identify them. Here we look at two more species of Blechnum. Hard Water-fern (Blechnum wattsii) and Soft Water-fern (Blechnum minus).

Blechnum wattsii – (Hard Water-fern) is much more common than the Soft Water-fern at Tarra Bulga and is found in both Cool Temperate Rainforest and Wet Schlerophyll forest areas. It has tough dark green fronds, a key feature is that the lower leaves (pinnae) on each stem (rachis) are only slightly smaller than the others.

Blechnum minus – (Soft Water-fern) is locally more restricted in its distribution and mainly confined to the banks of water-bodies. It’s fronds are a lighter shade of green and the margins of the pinnae are more undulating or wavy. A key feature of their identification is that the lower leaves (pinnae) on each stem is are much shorter than the rest and they are also widely spaced apart.

Both species are dimorphic meaning that the fertile fronds that contain the spores are different to the regular fronds, for both of these species they are a lot more slender than the regular fronds.

Related Posts

Local Cassinias

This is the time of year when most of the daisy species in Tarra Bulga are in flower. A number of species look quite similar and a bit of knowledge is often needed to tell one from another.They are all medium shrubs with narrow linear leaves and similar looking cauliflower like flower-heads.

One group are the Cassinias’ there are three separate species and all of them occur in the more open and exposed sections of the park rather in the shaded and protected gullies

Cassinia aculeata – (Common Cassina or Dogwood) has the the shortest and narrowest leaves of the three. If you look underneath the leaves you can see that they are curled over at the edges. Another distinguishing feature is that the new flowers are sometimes pink rather that white.

Cassinia longifolia – (Shiny Cassinia) has broader and longer leaves and the new leaves are noticeably shiny and sticky to touch. The underside of the leaves are covered in short dense hairs and the vein down the middle is very prominent.

Cassinia trinerva – (Three-veined Cassinia)Has leaves that are also broader and longer than Common Cassina, they are quite soft and not shiny or sticky. They have a big vein running down the middle of the leaf and two smaller veins that run a millimetre or two inside the leaf margins.

Ozothamnus ferrugineus (Tree Everlasting) is a fourth species that can be confused with the Cassinia’s as it is a similar size and has similar leaves. It’s leaves are around the same size as Cassinia longifolia (Shiny Cassinia) but its leaf margins are usually a little wavy. With close examination the flowers are clearly different to Cassinias, they have little bracts around the individual florets.