Transcript Pteris tremula

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.
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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 phase
s. 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 freeliving organism, whereas the gametophyte of the
gymnosperms and angiosperms is dependent on the
sporophyte.
• Life cycle of a typical fern:
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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.