do you know how many species of
flowering plants there are there are
quarter of a million at least those are
the ones we know about quarter of a
million species of flowering plants and
flowers are a real bugger they're pretty
difficult for plants to produce they
take an enormous amount of energy and a
lot of resources why would they go to
that bother and the answer of course
like so many things in the world is sex
I know what's on your mind when you're
looking at these pictures and the reason
that sexual reproduction is so important
there are lots of other things that
plants can do to reproduce you can take
cuttings they can they can sort of have
sex with themselves they can pollinate
themselves but they really need to
spread their genes to mix with other
genes so they can adapt to environmental
niches evolution works that way now the
way that plants transmit that
information is through pollen some of
you may have seen some of these pictures
before as I say every home should have a
scanning electron microscope you'll be
able to see these and there is many
different kinds of pollen as there are
flowering plants and that's actually
rather useful for forensics and so on
most pollen that causes hay fever for us
is from plants that use the wind to
disseminate the pollen and that's a very
inefficient process which is why it gets
up our noses so much because you have to
check out masses and masses of it hoping
that your sex cells your male sex cells
which are held within the pollen will
somehow reach another flower just by
chance right so all the grasses which
means all the cereal crops and most of
the trees have wind-borne pollen but
most species actually use insects to do
their bidding and that's more
intelligent in a way and because the
pollen they don't need too much of it
the insects and and and other species
can take the pollen transfer it directly
to where it's required so we're aware
obviously of the relationship between
insects and plants there's a symbiotic
relationship there whether it's flies or
birds or bees they're getting something
in return and that thing in return is
generally nectar
sometimes that symbiosis has led to
wonderful adaptations the hummingbird
hawkmoth is beautiful in its adaptation
the plant gets something and the hawk
moth spreads the pollen somewhere else
plants have evolved to create little
landing strips here and there for bees
that might have lost their way there are
markings on many plants that look like
other insects these are the anthers of a
lily cleverly done so that when the the
unsuspecting insect sort of lands on it
the anther flips up and wops it on the
back with a great load of pollen that it
learn goes to another plant with is an
orchid that so it might look to you as
if it's got jaws and in a way it has it
forces the insect to crawl out getting
covered in in pollen that it takes
somewhere else orchids there are 20,000
at least species of orchids amazingly
amazingly diverse and they get up to all
sorts of tricks to try and attract
pollinators to do their bidding this
orchid known as Darwin's orchid because
it's one that he he studied and made a
wonderful prediction when he saw it you
can see that there's a very long nectar
tube that sort of descends down from the
from the orchid and basically what the
insect has to do in the middle of the
flower has to stick its little proboscis
right into the middle of that and all
the way down that nectar tube to get to
the nectar and Darwin said looking at
this flower I guess something has come
evolved with this and sure enough
there's there's the insect and I mean
normally it kind of rolls it away but in
its erect form that's what it looks like
now you can imagine that if nectar is
such a valuable a valuable thing and
expensive for the plant to produce and
it attracts lots of pollinators then
just as in sort of human sex people
might start to deceive they might say
I've got a bit of nectar do you want to
come and get it now this is a plant
this is a plant here that insects say in
South Africa just just love and they've
evolved with a long proboscis to get the
nectar at the bottom and this is the
mimic so this is a plant that is
mimicking the first plant and here is
the long proboscis fly that has not got
any nectar from the mimic because the
the mimic doesn't give it any natural
thought it would get some so not only as
the fly not got the the nectar from the
mimic plant it's also if you look very
closely at the just at this sort of head
end you can see that it's got a bit of
pollen but it would be transmitting to
another plant if only some botanist
hadn't come along and stuck it to a blue
piece of card now deceit
carries on through the the plant kingdom
this flower with its black dots and they
might look like black dots to us but I
tell you to a to a male insect of the
right species that looks like two
females who are really really hot to
trot and when the insect gets there and
lands on it dosing itself in pollen of
course that it's going to take to
another plant if you look at the every
home should have one scanning electron
microscope picture you can see that
there are actually some patterning there
which is three-dimensional so it
probably even feels good for the insect
as well as looking good and these
electron microscope pictures here's one
of an orchid mimicking an insect you can
see that different parts of the
structure have different colors and
different textures to our I have very
very different textures to of an insect
might perceive and this one is evolved
to mimic a sort of glossy metallic
surface on that you see on some beetles
and under the scanning electron
microscope you can you can see the the
surface they're really quite different
from the other surfaces we looked at
sometimes the whole plant mimics an
insect even to us I mean I think that
looks like some sort of flying animal or
beast as it's a wonderful amazing thing
this one's so clever it's called
obsidian I think of it as insidious
sometimes so the right species of bee
this looks like
another very aggressive bee and it gave
him box it on the head lots and lots of
times to try and drive it away and of
course covered itself with pollen the
other thing it does is that this plant
mimics another orchid that has a
wonderful store of food for insects only
this one doesn't have anything for them
so it's deceiving on two levels fabulous
and here we see Alang Alang the
component of many perfumes actually
smelts along with someone earlier and
the flowers don't really have to be that
gaudy there they're sending out
fantastic array of scent to any insect
that will have it this one doesn't smell
so good this is a flower that really
really smells pretty nasty
and is designed again evolved to look
like carrion and so flies flies love
this they fly in and they they pollinate
and this which is a hillock o dis Arras
as is also known as dead horse Arum I
don't know what a dead horse actually
smells like but this one probably smells
pretty much like it's for a really
horrible and blowflies just can't help
themselves they fly into this thing and
they fly all the way down it they lay
their eggs in it thinking it's a nice
bit of carrion and not realizing there's
no food for the eggs the eggs are going
to die but the plant meanwhile has
benefited because the bristles release
and the the flies disappear off to
pollinate the next flower fantastic
here's Erin Erin maculatum lords and
ladies or cuckoo pint in this country
photograph this last weekend in Dorset
this thing heats up by about 15 degrees
above ambient temperature amazing and if
you look down into it this is sort of
down past the spadix
the Flies get attracted by the heat
which is boiling off volatile chemicals
at little midges and they get trapped
underneath in this container they drink
this fabulous nectar and then they're
all bit sticky at night they get covered
in pollen right rich sort of showers
down over them and then the bristles
that we saw above they sort of wilt and
allow all these midges out cover
in Poland fabulous thing now if you
think that's fabulous this is one of my
great favorites this is the philodendron
saloon okay anyone here from Brazil
you'll you'll know about this plant this
is the most amazing thing that sort of
phallic bit there is about a foot long
okay
and it does something that no other
plant that I know of does and that is
that when it flowers that's the the
spadix in the middle there for a period
of about two days it metabolizes in a
way which is rather similar to mammals
right so instead of having starch which
is the sort of food of plants it takes
something rather similar to brown fat
and burns it at such a rate that is
burning fat metabolizing the about the
rate of a small cat okay that's you and
that's twice the energy output weight
for weight than a hummingbird
absolutely astonishing this thing does
something else which is unusual not only
will it raise itself to 115 Fahrenheit
43 or 44 degrees centigrade for two days
but it keeps constant temperature
there's a thermo regulation mechanism in
there that keeps constant temperature
now why does it do this I hear you ask
now wouldn't you know it there's are
some beetles that just love to make love
at that temperature and they get inside
and they get it all on and and the plant
showers them with pollen and off they go
and pollinate and what a wonderful thing
it is now most pollinators that we we
think about are insects but actually in
the tropics many birds and butterflies
pollinate and many of the tropical
flowers are red and that's because
butterflies and birds see similarly to
us we think and can see the color red
very well alright but if you look at the
spectrum and birds and and us we see red
green and blue and see that spectrum
insects see green blue and ultraviolet
and they see various shades of
ultraviolet so there's something that
goes on off the end there and wouldn't
it be great if we could somehow see what
that is I hear you ask well yes we can
so what is an insect seeing last week I
took these pictures of
Rock Rose Healy anthem um in Dorset
these are little yellow flowers like we
all see little yellow flowers all over
the place and this is what it looks like
with visible light this is what it looks
like if you take out the red most bees
don't perceive red okay and then I put
some ultraviolet filters on my camera
and took a very very long exposure with
the particular frequencies of
ultraviolet light and this is what I got
right and that's a real fantastic bull's
eye right now we don't know exactly what
a bee sees because you know any more
than you know what I'm saying when I
call this red right you you know we
can't know what's going on and let alone
an insect another human being mind but
the contrast will look something like
that
okay so you know it's standing out a lot
from the background there's another
little flower a different range of
ultraviolet frequencies different
different filters to match the
pollinators and that's the sort of thing
that it would be seeing just in case you
think that all yellow flowers have this
property no no flowers damaged in the
process of this shot it's just when you
know attached to the tripod not not
killed then under ultraviolet light look
at that and that could be the basis of a
sunscreen because sunscreens work by
absorbing ultraviolet light so maybe the
chemical in that would be useful
finally there's there's one of evening
primrose that beyond was lit from Norway
sent me fantastic hidden patent and I
love the idea of something hidden I
think there's something sort of poetic
here that these pictures taken with
ultraviolet filter the main use of that
filter is for astronomers to take
pictures of Venus actually the clouds of
Venus right that's the main use of that
filter Venus of course is the God of
love and fertility which is the the
flower story and just as flowers spend a
lot of effort and trying to get
pollinators to do their bidding
they've also somehow managed to persuade
us to plant great fields full of them
and give them to each other at times of
birth and death
and particularly at marriage which when
you think of it is the moment that it
sort of encapsulates the the sub
transfer of genetic material from one
organism to another thank you very much