Pteris tremula Classification:Kingdom:Plantae Division:Polypodiophyta Class:Polypodiopsida Order:Polypodiales Family:Pteridaceae Genus:Pteris Species:P. tremula Varieties :Pteris tremula var. caudata Pteris tremula var. minor Pteris tremula var. pectinata Pteris tremula var. tremula

General characters :Pteris tremula is a terrestrial fern, with its fronds arising from the ground up to 1.3 m (4 ft), rarely up to 2 m (7 ft) tall. The stipe is brown. The light green lacy compound fronds may reach 2 m (7 ft) in length and are 3-pinnate or more. The brownish sori line the undersides of the frond margins.[4] Unlike Pteris vittata and other Pteris species, it is not able to hyperaccumulate arsenic and is damaged by levels as low as 25mg/kg in the soil. Habitat:The range within Australia is Central Australia (Northern Territory), eastern South Australia, Queensland, eastern New South Wales, Victoria and Tasmania. It is also found on Lord Howe and Norfolk Island, New Zealand, and the Kermadec Islands and Fiji. It is found in sheltered habitats in wet sclerophyll and rainforest.

Life cycle of a typical fern: REPRODUCTION Ferns are vascular plants differing from lycophytes by having true leaves (megaphylls), which are often pinnate. They differ from seed plants (gymnosperms and angiosperms) in their mode of reproduction—lacking flowers and seeds. Like all other vascular plants, they have a life cyclereferred to as alternation of generations, characterized by alternating diploid sporophytic andhaploid gametophytic phases. The diploid sporophyte has 2n paired chromosomes, where nvaries from species to species. The haploid gametophyte has n unpaired chromosomes, i.e. half the number of the sporophyte. The gametophyte of ferns is a free-living organism, whereas the gametophyte of the gymnosperms and angiosperms is dependent on the sporophyte. Life cycle of a typical fern: A diploid sporophyte phase produces haploid spores by meiosis (a process of cell division which reduces the number of chromosomes by a half). A spore grows into a haploid gametophyte by mitosis (a process of cell division which maintains the number of chromosomes). The gametophyte typically consists of a photosynthetic prothallus. The gametophyte produces gametes (often both sperm and eggs on the same prothallus) by mitosis. A mobile, flagellate sperm fertilizes an egg that remains attached to the prothallus. The fertilized egg is now a diploid zygote and grows by mitosis into a diploid sporophyte (the typical "fern" plant).

ECONOMIC IMPORTANCE Many ferns are grown in horticulture as landscape plants, for cut foliage and as houseplants, especially the Boston fern (Nephrolepis exaltata) and other members of the genus Nephrolepis. The Bird's Nest Fern (Asplenium nidus) is also popular, as is the staghorn ferns(genus Platycerium). Perennial (also known as hardy) ferns planted in gardens in the northern hemisphere also have a considerable following. Fern tubers were used for food 30,000 years ago in Europe.[9][10] Fern tubers were used by the Guanches to make gofio in the Canary Islands. Ferns are generally not known to be poisonous to humans.