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Cell types
Trichomes
A Trichome is an epidermal "hair".
Trichomes can be singular or
multicellular.
A major function of the trichome is
thought to be in plant defense
against insects.
Chemicals produced in the glandular
tip can deter feeding or the
trichome can physically prevent the
insect from reaching and feeding on
the leaf.
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Cell types
Trichomes
Look close and you can see the tiny hairs (trichomes) on the back of these
tomato flowers. There is some evidence that some types of chemicals
produced in tomato trichomes can prevent insect attack.
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Cell types
Trichomes
Trichomes can appear as singular "hairs" or they can be branched as seen in
these two stellate trichomes. Trichome shape is indicative of a particular
plant species and has been used in taxonomy to identify plants.
Branched trichomes
Single trichomes
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Stellate trichomes
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Cell types
Trichomes
Using an electron microscope you can see the beautiful
shapes of trichomes.
A trichome without
a glandular tip
A trichome with a
glandular tip
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Trichomes
Trichomes contain many different
types of secondary chemical
products.
Some are useful
products like fragrances or
flavors as in mints.
Trichomes also function to shade
the leaf for plants native to hot,
arid climates.
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Cell types
Trichomes
Trichomes
grow
from
epidermal cells and can
make striking patterns on
leaves and stems like on
this begonia leaf.
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Trichomes
Trichomes
can
also
contain
irritants that cause rashes in
people like this stinging nettles
(Urtica dioica).
These trichomes actually inject
irritating chemicals into the skin
when touched causing the “sting”.
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Cell types
Trichomes
Some plants like this fuzzy
Kalanchoe have leaves covered
with hairs (trichomes).
This may shade the leaf and
make it more adapted to a
hotter, drier climate.
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Cell types
Trichomes
The most specialized trichomes are
found in insect eating plants like this
sundew (Drosera). The trichomes glisten
with exudate that trap and digest the
insect (red arrow) while the leave curls
around it.
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Cell types
Trichomes
Tradescantia stamen hairs are large
trichomes.
Stamen hairs are made of 10 to 30
large cells connected end to end.
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Cell types
Trichomes
Trichomes are very active cells. In
stamen hairs of Tradescantia, it is easy
to see this activity.
The cellular components move around
the cell in strands of cytoplasm.
The cytoplasm is in strands that move
around the vacuole near the outside of
the cell along the cell wall.
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Cell types
Trichomes
Cytoplasmic streaming in Tradescantia stamen hairs.
Click the image to see the movie.
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