frozen Greenland but why in this vast ice-covered Arctic waste such precise
floral engineering the world's smallest tracking station
Sardinia beautiful island in the Sun specialty kidnapping so why not a plant
which follows local custom and skills or shall we go to Central America where in
gathering ingredients for an essential love potion insects unwittingly become
involved in a most bizarre encounter Africa could looks be more pure innocent
harness well in reality they conceal a nature which requires at least one death
to secure a new generation and Australia a pod explodes scattering seeds
everywhere and life begins again plants hold up their flowers to the light to
heaven and the Sun to be noticed they are designed for one thing only sex you
see the flowers themselves are sex organs and there is no point in
concealing them they burst upon the world with the insistence that life has
most flowers are bisexual having both male and female organs the female
receptive stigma leading to the ovary and the male anthers that produce pollen
they are ready and waiting for the great moment
far beyond normal limits of the eye a masterpiece of design the pollen of each
species is as individual as a fingerprint it must fit the physical and
chemical features of the stigma as precisely as a key fits its lock of course
having both male and female organs in one flower it couldn't be easier it
would seem to be perfect for self fertilization and some flowers can do
just that but evolution requires that most plants be pollinated by another
plant of the same species and how on earth do we manage that when you're
literally rooted to the spot well each has developed an intriguing
speciality to bridge to overcome the physical separation from another of its
kind let's start in Australia for some species the bush fires which sweep
Western Australia every 10 or 15 years are essential to reproduction and right
here among the charcoal remains is just the kind of intriguing little
speciality we've been talking about in the spring following the desolation
there's a plant an orchid that has just enough energy to throw up one heart
shaped thumbnail size leaf and a very very very long stalk even though it's a
rare orchid it's no great beauty but nevertheless the inelegant shape is a
quite brilliant design for copulation but not with another flower no no
something much more fascinating than that
slowly fighting her way up through the still charred sandy ground a newly
hatched female a thin it wasp emerges and takes her first look at the world as
she lives underground she's no use for wings so she's wingless and like and
drab anything but beautiful the females climb for only one purpose they want to
find males then to go back underground to search out and paralyze beetle grubs
in which to lay their eggs like a maiden nervously waiting for a blind date she
adds the finishing touches at the same time releasing an absolutely
irresistible perfume and she waits to clasp her partner with open jaws
elegant the winged males hot on the scent and eager for action having
emerged a few weeks before the females and they actually start copulating in
flight he flies her to this flower there she feeds through him from the tip of
his abdomen and gets both sperm and food all at the same moment and probably the
only nectar meal of her life
then he flies her back home the honeymoon over she'll just disappear
underground forever so how does the wasp enter into an
affair with this unusual orchid a hammer orchid it could be coincidence that all
the females are still underground when the orchid flowers but it is quite
beyond coincidence when the flower assumes the shape mimics the body and
even gives off the scent of the female wasp and this precisely when there are
lots of sex-starved male wasps around the hinge joint the correct length of
arm a glistening sticky pad between two yellow pollen sacks at exactly the right
distance from the dummy wasp must have been grown with incredible accuracy it
is perfect for a bizarre coupling of wasp with flour
sufficiently deceived he tries to fly off with her but succeeds only in
catapulting himself into the orchids anthers at last his furry back peels
off the yellow pollen bearings hacks he gives up and tears himself free although
the go-between carries the pollen to other flowers for the orchids deception
to work he must visit another hammer orchid like the wasp visiting now
bringing male elements to receptive female parts with pollen crushed into its
stigma the hammer orchid is fertilized the little dummy female withers its
purpose served the orchids meager resources are now required for the
swelling seed pod the deception has worked perfectly but does it always if a
female wasp miss times her entrance is around before all the orchids are
pollinated or if the orchid hours late is he fooled
you
well only for a second
it would be hard to visualize a world without the beauty of grasses few people
realize that they too bear flowers the anthers float their pollen through the
air gambling that some may catch on the branching crystal like stigmas of the
female
for grasses and most trees sex is born on the wind huge pollen clouds
breathing life onto everything this blanket bombing mass proliferation is
effective but incredibly wasteful so why not an insect a sort of go-between to
deliver it with that personal touch there are millions of plants using energy
displaying flowers showing readiness for pollination crowding bunching for the
services of these little go-betweens wanting to be noticed so as humans for a
film festival can or somewhere they push it around dress it up extravagantly in
bright colors it pays to advertise
myriads of eye-catching shapes designs and patterns as blatant and gaudy as
Piccadilly Circus and the insects bewitched can be dazzled wondering whom
to call our next are given clear indications in their ultraviolet vision
exactly where to go
it is not a cozy relationship however and it's not for love alas flowers must
pay for service the hard cash currency of insects pollen itself highly nutritious
nectar wax for certain stingless bees to make their cells or the plant can
deceive its visitor by making the false offer of sexual satisfaction it is said
that the first biologist to discover this Australian ecumen wasp actually
releasing sperm into a flower it didn't dare publish their findings
but insects beware you are being used for there is a certain flower with which
any association however casual can lead to certain death as long as there are
rewards for favors and services rendered there will always be cheats those who
want food for free large bumbles with their long tongues easily probe the
nectar of comfrey telltale holes reveal where small bumblebees unable to get at
the nectar have chewed with their strong jaws to pillage and the honeybee soon
learns to draw from the nectar is without entering the flower without
touching the reproductive part without doing her stuff so plants have developed
quite amazing defensive strategies the teasel going as far as thwarting thieving
ants with a carefully constructed water trap or moat or consider this ginger it
actually employs ants to guard the flower against plunder by the wrong
visitor and they are paid from nectar is evolved especially for the ants use give
a little take a little there's a rationale
but in nature what appear to be cozy understandings come in fact from the
pursuit of ruthless self-interest the most seemingly innocent offerings can
sometimes be deadly the african water lily on the second day of its life quite
quite harmless
and what a feast hundreds of stay men's all capped with pollen like giant lollipops
and away he flies but what a difference on the first day of its life for only
then does the lily have that awful need to kill does it have that inviting pool
of crystal clear liquid in the center
what looks like nectar is not nectar at all it is a deadly poison and what is
more the overhanging stay men's at this moment as smooth as silk
dead just a few last nervous twitches night falls and the reason for what
seemed a pointless death is now revealed inside the floral tomb the lethal liquid
washes the pollen grains from the victim's body souvenirs of older kinder
lilies they sink to fertilize the eggs below
so remember if you're going to drop in on a lily be sure to get your timing
right it can be more than your life is worth to visit a virgin flower as our
little hover fly did the competition for survival molds all living things for
ever greater success in reproduction and plants are no exception many flowers
have evolved characteristics to suit only certain pollinators night flowers
sent it for moths some methods are very sophisticated buzz pollination the
release of pollen by ultrasonic vibrations digitalis fox gloves or
finger hats popular poison for the faint of heart lures bees to the bottom
thimbles first to make sure all are visited in turn the fig word has a
special flower for wasps hyenas of the insect world only not quite special
enough to prevent a marauding ant from stealing nectar without transferring
pollen the trigger plant is a brilliant design
a hit and a miss
many desert plants rely on ants the whole design of this North American
plant is typical it grows near the ground leaves and stem intertwined to
form aerial walkways so aunts can go from nectar to nectar with minimum
effort the flowers themselves are minute they don't need to be big they're not
signaling to insects over long distances as the ant takes the nectar the stamen
anoints its head with a few pollen grains or the next plant but of course
not all go betweens our insects anything that wittingly or unwittingly can
reliably ferry pollen from flower to flower will do the pig may possum eats
moths insects in fact almost anything it eats pollen too and in doing so
transfers it and becomes one of a very select band of pollinating mammals
but it is flight which makes most creatures good pollinators and some
plants have evolved to make use of birds providing huge quantities of nectar even
changing their flowers in size shape and color look at the kangaroos poor it
provides a furry stem for a honey eater to perch on as it draws from the
nectar is the plants mechanism works powdering the bird's head with pollen
this no lack of invention with Strelitzia the sex organs themselves form
the perch cleverly designed to be totally insecure it's like trying to
balance on the slippery pole and inevitably the bird puts its foot in it
here and elsewhere no doubt until recently there was argument about
fertilization of the magnificent African proteas for some species birds are
obvious candidates they live on the plants guarding their nest and food
supply at the same time and the proteas just to make sure expose their flowers
to the heavens so that sunbirds from all over can take their choice then why do
some species have hidden flowers near the ground growing downwards
this protea has opted for mice less conventional but possibly more reliable
already totally adapted to a nectar diet is the Australian honey possum the
trapeze artist of the marsupial world
with half a dozen teeth and enormously long tongue it has an amazing capacity
for drink albeit nectar
grasping fingers and a gripping tail enable it to live in the tops of trees
many of which have evolved flowers which are for a copious supply of nectar
especially for this delightful little Diplom
in Central America nectar rich flowers have evolved for hummingbirds and at
last the secret of ginger's love life can be revealed guarded by ants it's
strictly for the birds
with prodigious appetites for nectar hummers have become the willing slaves
of the plant reproductive strategy to be successful plants may appear to us to be
beautiful ugly even revolting depending on whom they're trying to attract whom
to deceive in style more appropriate for ancient Egyptian Kings blowflies pay a
last tribute to the dead by laying their little gifts their eggs upon the corpse
soon their maggots have the gruesome but necessary task of eating the world free
from putrefying flesh and stinking carrion
it is difficult to believe that I'm a beautiful uninhabited island off the
coast of Sardinia there is a plant which has adopted these very blowflies as it
go betweens this lily a kind of air is surely a conception of the market decide
in the chamber below is a most elaborate structure a dark passage with a huge
central column supporting a battery of male stamens beneath is a crown of
spikes guarding a second battery of female flowers the perfume of this flower
the stench of a rotting corpse is so powerful that it is irresistible to flies
which swarm in from all over the island from the first day the flower opens
female flies land and start to search for the dankest and darkest place to lay
their eggs they make for the deep hairy throat which becomes as they pass the
guard hairs a one-way street up which there can be no return for at least two
days or maybe not at all they feed on nectar oblivious of danger
any pollen they might by chance be carrying is brushed off on the receptive
female flowers as they reach the murky depths so good so realistic is the foul
smell of carrion so brilliant the deception the flies actually lay their
eggs pointlessly or even though they hatch the maggots find no real carrion
nothing on which to feast and die of hunger
on the second day of kidnapping the male stamens burst open and shower the
wretched captives with sticky pollen
the first casualties occur in this insect charnel house exhausted flies
are trampled to death by fellow inmates however to kill is not the intention nor
is it at all in the plants interest on the third day the guard hairs with her
and the survivors find themselves suddenly able to escape dusty with pollen
they emerge groggy but still eager to find a bit of real rotting flesh or as
the plant intends enter another chamber of horrors but why is this Aram found
here only on some small Mediterranean islands the resident girls with their
chick births smelly regurgitated food and inevitable deaths are probably part
of the reason for they would naturally be blowflies about only to easily duped
and kidnapped of course there is a risk to the go-betweens but sometimes the
risk is to the pollen itself
water in which the first seeds of life were born still plays an important part
in floral reproduction like weightless moon white rocks these tiny male flowers
will float on the surface at the whim of the restless wind a flowering plant
which has returned to the world from which all plants come has readapted to a
life in water the extraordinary valisneria or ribbon weed produces
entirely separate male and female plants the female sends up a long coiled stork
at the end the tantalizing female flower rests in a shallow dimple in the surface
tension simultaneously a flask at the base of the male plant is forced open by
oxygen bubbles it releases tiny male flowers which start to drift up to the
surface where the female lies in wait but it's a hazardous voyage
pollen is nutritious each tender white morsel caviar to the fish world
it is of course absolutely essential that some get through the plant releases
more and more and it releases them at night of many thousands even with luck
perhaps only a hundred or so break the surface there they float like mini
icebergs until each transforms itself
petals bend over to form a raft pushing the pollen jewel like crystals up on a
glistening stalk exquisite and delicate they are nevertheless absolutely
functional
but even on the surface they are never safe there's always a jaws or two down below
the female covered with minute water repellent hairs weights
when the little rafts of pollen are within a couple of centimeters of the
female they are irreversibly set on a course to slide down the slippery slope
straight into her huge embrace and the fish which so eagerly gobbled the
flowers before will now be instrumental in dispersing the seeds
from pinpoint sized icebergs to the real thing Greenland in the full flush of a
five-week summer even then it's chill enough to send any pollinator into a
frozen stupa yet flowers are bound despite the cold reproduction is
imperative but it's awfully difficult to get things going and that's exactly the
problem but not perhaps for one little Arctic rose dry ass it has evolved a
method that matches space-age technology like a radio telescope the petals
reflect the Sun's rays as efficiently as gold foil the parabolic shape
concentrates warmth at the center exactly on the stamens and stigma in a
cold place heat and food are powerful attractions a visiting insect finds it as
much as ten degrees warmer in that private place in the Sun the insects are
hot and fit for flying after only a few minutes and as planned they go on to the
next plant with such a short summer the go-betweens must work around the clock
but then there are no nights the Sun never vanishes below the horizon in the
Arctic summer the strangest part of this plant is its rotating stem which allows
it to track the Sun 24 hours a day never more than two degrees of course
beautifully engineered the world's smallest tracking stations
floral strategies come in many shapes and sizes short and sweet on ice
strange and chancy under water
kidnapped and kept in Sardinia
delicate but deadly with Lily but no sexual encounter of the floral kind is
more strange than that found in the steamy still rainforests of South
America
trees crowding out the sky no gentle breeze to bear the magic dust of life
more orchids than any botanist can name and yet for many species there can only
be one pollinator only one bee to unlock the secret combination of its sex life
the orchid with the most complex flower the most bizarre and outrageous strategy
is coriander ease the bucket orchid it clings to branches with its roots
embedded in a nest of ants which guard it and supply it with nutrients but the
ants do not pollinate it this is done exclusively by a species of beautiful
iridescent orchid be the plants one and only pollinator in the early morning the
orchid opens almost immediately it begins to drip a clear fluid from two
glands into the bucket part of the flower at the same time the orchid
gives off a scent highly attractive to its pollinators its little male bees
but the bees come because their chance of reproducing depends on what the
orchid is offering it is a waxy substance they scrape off with specially
modified front legs to make a perfume a sort of aphrodisiac essential to attract
and stimulate female bees no wonder males fly in from up to five
miles away in the ensuing dogfight the inevitable accident occurs though it's
no accident as far as the orchid is concerned the purpose of the fluid now
becomes clear unlike the water lily the orchid's intention is not to kill its
victim early enough it must now start to help him to escape
the bee is on the point of drowning when it discovers a small escape tunnel with
a rather conveniently placed step
just when it seems nothing can prevent escape the top and bottom of the tunnel
flows in holding the bee in a vice-like grip
struggle and strain as he might he is held firm while the orchid glues two
little yellow pollen sacks on his back
it takes about ten minutes for the glue to set and only then does the orchid
release him the bee is now fully fledged to go between but he must wait to dry
to complete his escape but the orchid's sexual plan is far from complete bees
which bear no pollen merely pass through the system it must wait for one kind
pollen sacks from another orchid before it can be fertilized but what a
difference when this bee tries to make its escape the flower has a device which
grabs the pollen sack from his back
there the amazingly complex plan has worked
despite its apparently foolproof design
Corianthes is taking an awful risk where its bees to disappear even become
scarce in numbers this beautiful orchid would vanish forever whatever the plant
whatever the means the seeds must set and it is of great concern to us all
those seeds contain our future too floral sex is no less important than
human or animal sex without it there would be no life on earth as we know it
nothing
You