Staghorn Fern	Elkhorn Fern	Birds Nest Fern	Basket Fern
Scaly Tree Fern	Ribbon Fern	King Fern	Hare's foot Fern
Tassel Fern	Maidenhair Fern	Coral Fern	Fern Facts! Evolution & Reproduction  of Ferns

FERN FACTS!

• Worldwide there are over 12,000 species of ferns.

• The Wet Tropics is home to 65% of Australia's fern species.

• In Australia there are 390 native species of ferns, 47 species of fern allies, 44 species of conifers and 39 of them are endemic.

• Forty fern species are endemic to the Wet Tropics.

Epiphytic Ferns

• Epiphytic ferns are one of the most common features in rainforests.

• They grow on the trunks and limbs of trees but unlike parasitic plants such as mistletoe, do not steal nutrients from their host tree.

• They survive instead on rainwater and the nutrients they get from trapped fallen leaves.

• Sometimes the host tree taps into the fern though. Roots have been found growing from the host tree into the epiphytes.

'The Name Gondwana, given to the original super continent of Australia was a part, comes from a region of India where the fossil seed fern Glossopteris was first described. The widespread geographic distribution of this genus in ancient times was one of the clues which led to the realisation that the continents had once been joined.'
Courtesy of: Environmental Protection Agency, Cairns.  

Evolution & Reproduction of Ferns

• In the evolutionary development of plants, ferns represent a great advance on all previous models. The surface cells of an aquatic algae are able to absorb nutrients and water, on land it is necessary to divide up the tasks, a step which makes the plants more adaptable.
  

• Roots were a revolutionary new feature dedicated to seeking out less accessible sources of water, thus allowing plants to move inland. 
• They also served to stabilise the larger models.
• Water and nutrients, taken up by the roots, had to reach other parts of the plant so a plumbing system - the vascular system -evolved. 
• Woody vessels (xylem) performed this function, moving water and nutrients upwards. 
• These vessels had a duel function, providing rigidity to the tissues. 
• With these load-bearing structures the plants were able to grow much taller and reach up to the light.
  
• Leaves were another fern invention - a system of solar panels dedicated to capturing the energy of the sun and turning it into food. 
• Exposed to the air, these had to be sealed to prevent the water gathered by the roots from leaking away so a waxy skin (cuticle) was developed. 
• Since the process of photosynthesis requires an intake of carbon dioxide from the atmosphere and waste oxygen must be released, special design features in the cuticle - pores - allowed this exchange of gases to continue.
  
• Another plumbing system was needed to move the sugars and other photosynthetic products from the leaves to the rest of the plant. 
• This function was performed by another new system of vessels, the phloem.
• Although ferns were among the earliest vascular plants (algae, lichens, mosses and liverworts are all classified as non-vascular plants) they were not the only ones.
• The fossil records tell us that at one time the world was dominated by massive clubmosses, giant horsetails and others which created magnificent forests 45m or more in height as they used their newly developed vascular systems to reach higher and higher in competition for sunlight.
• Many of these plants are now extinct, their relatives hanging on comparative obscurity.

                Sexual links with the past

• Although ferns are structurally more advanced than mosses, like the more primitive algae and mosses their sex life involves two generations and a dependence on water.
  

• Spores are produced by the fern plant in spore cases, usually beneath the leaf.
  

• When released, each spore grows into a tiny heart-shaped structure known as the thallus which, in turn, produces male sperm cells at the pointed end and female cells in the notch.
  

• In the presence of water, the sperm burst free from the thallus and, attracted by chemicals, swim to the female cells.
  

• Following fertilisation, an adult plant develops, eventually dwarfing its `parent' thallus. 

• Curiously this large spore-producing fern plant is the equivalent of just the tiny spore capsule and stalk of the moss plant while the much more obvious green moss plant is the equivalent of the tiny fern thallus. 

• Both produce sex cells.
  

• Many ferns can, of course, increase their numbers asexually by spreading their rhizomes-stems which are either below the soil surface or just above it. 

• Roots grow down from the rhizomes while fronds sprout from the top.

Courtesy of: Environmental Protection Agency, Cairns.  

While many of the plants in the rainforest have been around for millions of years, ferns have been around for much longer than that! They appeared in the fossil record dating back to 325 million years ago. They are one of the earliest vascular plant forms on the planet (plants which circulate water internally) and they preceded the flowering plants, the conifers and even the cycads - all of which have a more advanced means of reproduction. 40 species of ferns are endemic to the Wet Tropics (occur nowhere else) and there are many interesting species but only a few special ones are profiled here.

The King Fern (Angiopteris evecta) looks superficially more like a palm crown growing directly out of the ground but this is actually a relic fern from the late Paleozoic era. This is the only species from its genus in Australia but it does occur elsewhere in Southeast Asia/Oceania. The fronds might be the longest in the world for a fern, reaching as much as 5m (16 ½ feet). A good place to see King ferns is the Nandroya Falls track in Palmerston National Park, south of Cairns and along the road to Cape Tribulation.

A primitive looking fern indeed is the Tassel fern and with good reason - its fossils have been identified to much larger specimens from the Carboniferous period. Two very different forms of the Tassel fern (also known as Clubmoss) are almost opposite to each other in habit. The first is a ground creeping version sometimes called the Pine Tree fern (Lycopodiella cernua) as it resembles miniature pine trees only 25cm (10 inches) tall. It prefers open sun and spreads along the ground, sending up vertical stems from along its length. If any of the tips of the erect fern should meet the soil, a new plant sprouts from the tip and grows upward to become a new vertical plant that sends out creepers. Visitors to the Flecker Botanic Gardens in Cairns can see this plant on display.

The other Tassel fern group of interest is an epiphytic one (grows on top of another plant but is not parasitic) which has been grown frequently as a hanging plant. The Common Tassel fern (Huperzia phlegmaria) likes warm, humid conditions with good air flow. At the end of each long "cat-tail" is a shorter green stem with tiny cones along its length. These contain the material for a most interesting means of reproduction: the cones release spores which drop into water, some spores being male and others being female. These spores are then fertilised in the water as they collide, becoming a seed which can then sprout a new plant.
Wet Tropics Management Authority.