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Transcript Gnetophyta[1]

They are vascular seed bearing plants
that can grow as shrubs, trees, or vines
 There are about 70 present day species
of gnetophytes that are known placed in
just three genera
 Gnetophytes fall under the phylum of
Gymnosperms which are ancient
surviving seed plants
Gymnosperms are the most ancient
seed plants
 There are four groups of gymnosperms
that are found today
 They include gnetophytes, cycads,
ginkgoes, and conifers.
 All these plants reproduce with seeds
that are exposed
 Gymnosperms are also known as cone
bearers and it means “naked seed”
In Flowering plants the fruit or ovary wall
covers the seeds, in gymnosperms the
seeds are not covered in anything similar
to that, that is why they call it naked
 These plants are fruitless and they do not
produce flowers.
Ancestors of seed plants evolved to
survive in many places other plants
 The oldest plants included ferns and
 These ferns and mosses evolved into
plants with seeds during the
Carboniferous and Devonian periods
which were 300-400 million years ago
There are three different types of
gnetophytes on earth
 They all are very simmilar but have their
differences and are used for very unique
and benificial reasons
 The three types are
2. Gnetums
3. Welwitschia
Epherda are mostly found in dry climates
mainly in the norther hemisphere, across
south Europe, north Africa and central
asia and mainly plant grows where it can
get direct sunlight. example : deserts
 Epherda is very beneficial for medical
purposes because it is used to treat
asthma, hay fever, and the common
The Chinese used this plant to cure
symptoms of the common cold
 American settlers used it as tea called
Mormon tea, and Squaw tea.
 Ephedra is still even used today in most
over the counter medicine and in fat
burning medicine
 These plants are mostly shrubby, with
small scale leaves and jointed scales
Gnetums is a type of gnetophyte that
are tropical evergreen trees, shrubs and
 Gnetums are very odd when being
compared to Gnetophytes because
they produce brad leaves with netted
venation that are very simmilar to the
ones found in flowering plants
 These Gnetums are found in South
America, Africa and most parts of China
Gnetums are mainly edible therefore you
can eat its seeds when there roasted
and is used as a leaf vegetable, some
are used as herbal medicine
 Gnetums are very special compared to
other gymnosperms because they have
high photosynthetic and transpiration
capabilities with also a high capacity of
Welwitschia grows from a short, thick,
woody trunk with only two leaves that
continuously grow from their base, and
long thick taproot.
 These plants grow very slow and are
endangered, but despite being
endangered, they live around for a long
These plants start of with two leaves and
they grow and end up looking like if it
had multiple leaves.
 They are mostly found in South Africa
and has male and female cones. They
can live for almost one thousand years
Most Gnetophytes are located in the
desert or mountain in Asia, Africa, South
America, and in the deserts of North
 They need to be exposed to constent
sunlight this is why you might find them in
All of these plants reproduce with seeds
that are exposed.
 The reproductive scales of these plants
are cluisterd into cones
 Most gnetophytes produce separate
female and male cones born on
separate male or female plants