Blechnum nudum 

Location & distribution maps

Phylogeny & links to associated information

Wikipedia links:       Monilophytes > Polypodiales > Blechnaceae > Blechnum nudum

Other links:    

Plant  information

Common name:         Fishbone Water Fern

Conservation status: unkown

Etymology:   

• From Latin blachnon, a fern, from Greek blēchnon

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Spores:                            

• Blechnum fernshave separate fronds for spore production

Leaves:         

• Typically has simple, pinnate fronds of length 40–60 cm

• Fronds have a short, thick stipe that is sometimes covered in small hairs

• The class of blechnum ferns are typified by having distinct fertile and sterile fronds

• Fertile fronds are easily distinguishable from sterile fronds in the fishbone waterfern

• Overall, sterile fronds tend to be more delicate in appearance, with a thinner longer stipe

• Fertile fronds are simply pinnate, like the sterile variety, but can grow to be much longer than sterile fronds in the fishbone fern

• Pinna are thin, with a rounder profile than the flat pinna of the sterile fronds

• Fertile pinna are curved towards the tip of the frond, and are much shorter than sterile pinna

• The longest pinna of the sterile ferns are in the middle of the frond, with length decreasing towards each end

Stem & branches: 

Roots:         

• The fern grows through an underground rhizomic stem, which spreads underground

• Fronds emerge from beneath the ground via the stipe

• Over time, one plant may spread its underground stems over a great distance

Habit:        

• A fern that grows up to a metre tall

Habitat:   

• Abundant in rainforest and eucalyptus forests in eastern Australia

• While it grows well in full shade, the fishbone waterfern will thrive in areas of full sun if enough water is available

• It can grow in a range of wet forests and thrives in areas of higher water availability

• Because of this, it inhabits moist, poorly drained sites

• Shade is an essential factor for the fishbone waterfern due to its need for water

• Poorly drained soils are also important for times of lower rainfall - this allows water to be retained in the soil, available to the plant, even when rainfall is low

• Thus this fern will often be found growing in roadside ditches where sun is plentiful, but water pools after running off roads

• Creek beds are a similar, naturally occurring high water low rainfall habitat

• Fertile soils allow the waterfern to propagate and become abundant in wet eucalypt and rainforests

• In most suitable habitats, this waterfern grows abundantly

Distribution:                  

• Grows in all Australian states except for Western Australia

Additional notes:     

• The species is placed in the genus Lomaria in the Pteridophyte Phylogeny Group classification of 2016 (PPG I), but is often retained in genus Blechnum as Blechnum nudum.

• Reproduction and propagation

  • The fishbone waterfern displays a life cycle typical of ferns

  • Aside from having separate fronds for spore production, the fishbone waterfern shows a typical sexual reproductive process to most ferns

  • Vegetative growth is another strategy used by the fishbone waterfern to increase in number and size

  • This asexual reproduction is common amongst ferns

• Uses

  • The fishbone waterfern is commonly sold in nurseries as an ornamental plant

  • Its hardiness and aesthetic qualities combine to make a plant that is popular among gardeners

Sources of information:

• https://en.wikipedia.org/wiki/Lomaria_nuda (2023)