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Midwinter and the countryside is so still it seems almost lifeless.

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But these trees and bushes and grasses around me are living organisms, just like animals,

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with the same sort of problems as animals face in their lives if they are to survive.

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They have to fight one another; they have to compete for mates,

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and they have to invade new territories.

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We are seldom aware of these dramas because plants live on a different timescale.

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But these days we have ways of speeding things up visually

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and you can see just how dramatic the lives of plants can be.

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Condense three months into 20 seconds,

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and the desolation of winter quickly warms into the riot of spring.

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Speed a week into a minute 

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and you can sense the urgency with which the ground-living plants race to unfurl their flowers.

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Wood anemones nod attentively at the sun as it rises and sets each day.

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Above, hazel leaves, moving to the same rhythm,

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pulse as they expand to their full size.

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Beneath them, the broad leaves of docks are rising from the ground.

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Foxgloves gape almost alarmingly as they invite insects to come and collect their pollen.

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Strange though it may seem, some plants can move not just their flowers and leaves,

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but can travel from place to place. 

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Take, for example, this bramble.

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Of all the woodland plants,

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this is one of the most aggressive.

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It waves its shoots agitatedly from side to side as if feeling for the best way forward.

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And when a shoot settles on its course, it thrusts ahead relentlessly.

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The stem's backward-pointing spines give it the grip it needs

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to climb over almost anything that stands in its way.

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It can advance as much as three inches in a day.

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The shoot will put down rootlets 

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and new territory will be annexed to the bramble's empire.

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Other adult plants travel even faster.

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The birdcage plant lives in California,

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but the desert dunes are always moving and a site becomes exposed,

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so the plant must find a new place. 

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This plant is now dead, but within it there is still life.

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These tiny particles are the next generation.

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Each contains complete genetic instructions for rebuilding an adult plant like this.

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These small grains are the reason most plants do most of their travelling.

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Some of these genetic particles are, in fact, microscopic.

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Smallest of all belong to fungi.

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Fungi are not, to be accurate, plants at all

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they belong to a kingdom on their own

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but their spores are in many ways similar to seeds.

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A single puffball produces so many that someone has calculated that if, for two generations,

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every spore grew into an adult, the resultant mass of puffballs

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would be 800 times the volume of the earth.

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Like the birdcage plant, a puffball can be carried along by the wind,

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but the real travelling is done by the spores that are knocked from it in clouds, like smoke.

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In autumn, other smaller fungi appear on the woodland floor.

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Earthstars.

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Their appearance when they emerge gives little hint of how complex they will become.

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In the damp autumn air, the earthstars transform themselves.

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They open at this time of the year to take advantage of the falling rain.

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A drip gives them the energy

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to propel their spores into the air.

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Flowers also use the wind to transport their seeds

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and few do it more successfully than dandelions.

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As their petals fall their flower heads, over a period of one or two weeks,

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are transformed into wonderfully intricate globes,

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each a precise array of a hundred or so seeds, all awaiting the wind.

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Their seeds are much heftier than the spores of fungi.

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For them to fly, special apparatus is needed.

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Each is fitted with its own individual parachute.

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It is so efficient that a breeze carries the seeds high into the sky.

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In this dense crowd of adult plants,

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 there's no room for the next generation.

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The seeds must get away, and the wind will take them for miles.

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Trees have a particular advantage when despatching their seeds by air  their height.

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The farther it falls, the farther it travels.

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And these cottonwood trees 

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need only provide their seeds with straightforward fluff.

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But this, because of their height, is enough to carry them for miles.

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Every summer, the waters of the Great Lakes of North America become thickly flecked

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with cottonwood seeds around their margins.

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A few will wash up on distant shores and germinate.

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Most will be lost. But the seeds are so numerous it's of no consequence whatever.

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There is much less wind in the tropical rain forest.

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The humid air hangs as a mist,

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while below, there is seldom even a breath in the air.

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A plant here has to give its seeds very good flying equipment indeed.

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And none does that better than this liana in Borneo.

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Aircraft designers have tried to build a wing as efficient as this this one  but failed.

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Even the faintest updraught produced by the slightest thermal

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is enough to lift this little glider with its seed passenger, and so extend its flight.

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Plants preceded humanity in building fixed-wing gliders and not only gliders.

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They created helicopters too...

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..sycamore seeds.

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The balance between the weight of the seed and the length and width of the wing is perfect.

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A slightly heavier seed or a shorter and narrower wing

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and the whole thing would fall like a stone.

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The tri-star plant produces a revolving seed with six blades

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and aircraft designers have yet to copy that.

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Or this.

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Plants also use explosives...

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..jet propulsion.

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This is a squirting cucumber.

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And this  Himalayan balsam.

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Its seed capsules are pumped full of liquid to such a pressure

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 that the slightest touch makes them explode.

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The force is so great

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that seeds can be shot away for as much as fifteen feet.

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Mesembryanthemum seed heads are opened by rain.

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It's the sudden absorption of water

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that powers their opening. 

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Once open, they expose a screen as taut as a trampoline.

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Raindrops bounce off it, taking the seeds with them.

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Water provides many plants with the power they need for travelling.

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It can shift really heavy, bulky ones.

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Beside many tropical rivers, there hangs the biggest of all seed pods  the sea bean.

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These huge containers house one of the most successful of all vegetable travellers.

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There is a groove between each seed, so that each can fall away in its own separate packaging.

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One by one, the sea beans start on their voyages.

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This one is setting off down a small river in Africa.

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After a few miles perhaps even a few hundred miles

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the seed arrives at the mouth of its river and makes its way to the sea.

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It can voyage through groups of islands and out into the open sea

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to ride the great ocean currents for as much as a year and still remain alive.

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Its protective packaging

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may become so frayed and tattered that it disintegrates and releases the seed.

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But it's not a disaster, for the seed is able to float by itself.

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Many, doubtless, are lost at sea. But some eventually reach another and maybe a distant  coast.

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One has landed on a tropical beach in northern Australia,

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I've no idea where it came from. It could be from a tree a few miles up the coast,

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or from another continent. Sea beans land on the coast of Europe, having come with the Gulf Stream.

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Of course it's too cold for them there and they seldom germinate,

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but if they land in the tropics, they will almost certainly grow. There's one on this very beach.

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So, some plants send their seeds by sea, some by air.

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But most, in fact, use living couriers.

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Animals with hairy coats

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are easily conscripted.

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The burdock uses hooks hundreds of them.

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And very effective they are.

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Eventually the burrs are licked off, 

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picked off, or shaken off.

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If the burdock is lucky,

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 that will happen some distance from where the adult plant grew.

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Trousers will serve just as well as hairy coats,

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and shoes as hooves or paws.

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Here, in southern Africa, there is a creeper that uses not hooks but spikes.

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These things are called by the local people 'devil thorns' and you can see why.

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If an animal or human trod on that with a naked foot it would be very painful.

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But if you think that's bad, what about this?

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This is the seed case of the grapple plant.

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Animals with cleft hooves or relatively soft pads

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can be crippled by the grapple plant, but the bony, scaly feet of ostrich

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are particularly tough.

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They can carry this vicious hitchhiker for many miles

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without any ill effects.

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But there's another way of treating messengers.

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Instead of relying on chance encounters with them,

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you can tempt them with rewards.

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Many plants in these dry heathlands

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engage ants as carriers by attaching ant food to their seeds.

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If a seed lies out in the open for long here,

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a mouse or some other rodent will eat it. If it's to survive,

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it must get below ground quickly.

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And the ants take it there.

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The fleshy bit at the end is all the ants want.

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So the seed has now reached a safe resting place

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just below the surface of the ground.

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Plants bribe us too. And they make us fit in with THEIR timetable.

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This blackberry, for example, is not yet ready for my services.

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But as the flesh around the seeds sweetens, it announces the fact by changing colour.

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The blackberry's seeds will be more widely distributed

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if the plant is visited by a succession of different messengers

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so its berries do not all ripen simultaneously.

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Birds find them irresistible, 

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and quickly spot them. For black is a very conspicuous colour. And so, too, is red.

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Birds see colour the same way as we do.

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What is vivid to them is vivid to us.

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So rowans and yews, strawberries and plums,

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cherries and hawthorns, use red or black to summon birds to collect their fruit.

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Tropical figs produce much smaller fruit than their European relative,

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and they turn yellow. Even so, their message is widely understood.

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A tropical fig tree in fruit is a huge bonanza in the forest.

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All kinds of diners come to the tree. 

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As well as fruit-eating birds, they attract all kinds of mammals

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monkeys, squirrels and gibbons.

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The rhinoceros hornbill, with its huge beak,

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has to be a bit of a juggler.

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Now comes the important part. 

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Dozens of fruits containing hundreds of seeds are ferried miles away in the hornbill's crop.

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The flesh of the fruit will be digested

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and the seeds will be voided in a distant place in the forest.

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All forest canopies, however, do not have such a rich variety of fruit eaters as in Borneo.

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In New Guinea, there are very few mammals and no monkeys at all.

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The biggest creature on the ground is not an antelope or a great ape.

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It's a bird  the cassowary.

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Both male and female cassowaries have vividly coloured wattles, and the similarity between them

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and the fruits may not be coincidence.

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The wattles serve as social signals between the birds.

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Did plants adopt the same colours to call the birds' attention to their fruit?

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Or did the cassowaries make themselves more attractive to their mates

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by reminding them of a good meal? No-one can say for sure.

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What is certain is that cassowaries have no difficulty finding objects with these colours among the leaves.

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Visual signals, however, have their limitations as advertisements.

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In thick forest, you just can't see them unless you are quite close.

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But there is another medium  smell. It's less precise, but it works over greater distances.

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In Borneo, one fruit produces a smell so pungent

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that a sensitive nose can detect it from half a mile away.

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And some people like the taste of that fruit so much that they walk miles to find it.

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And so will others.

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This is it  the famous durian.

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I have to say that the smell, to my nostrils at any rate, is fairly disgusting.

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Like an open sewer with just a dash of coal gas.

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That's the rind. It's the advertisement. This is the fruit.

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That's very different.

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It's really pretty good.

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A kind of... slimy caramel creme, perhaps, would describe it.

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But if all Europeans aren't instantly durian addicts, all orang-utan are.

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Animals may carry seeds for long distances in their stomachs,

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but most get rid of them at random.

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For some plants, that is simply not good enough.

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The trewia tree in the forests of Nepal has a particular problem.

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Their seeds cannot germinate in deep shade.

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They have to be taken into a clearing if they are to stand a chance

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and one animal will do that for them,

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the great Indian rhinoceros.

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It's so fond of these fruits

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that they're called, locally, 'rhino apples'.

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The rhinos usually feed in the forest during the heat of the day,

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but in the cool of the evening they habitually move out into open grasslands.

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The grasslands are created by monsoon floods that, every few years,

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wash away parts of the forest. Rhinos visit them for the rich grazing.

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And out here, on regularly used communal middens,

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they perform the last of their daily duties.

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And there, neatly deposited with a ration of fertilising manure,

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are the seeds of the trewia.

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So young trewias sprout on the rhinos' dunghills.

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Other trees will grow, and the forest will colonise the grasslands.

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Then the trewia fruit, once more, will have a problem, and rely on the rhino to solve it.

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Sadly, this magnificent animal

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is getting rarer and rarer.

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Over millions of years of evolution, the trewia tree has established a link with it.

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But if the great Indian rhinoceros becomes extinct,

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the trewia itself may disappear from the grasslands and riverbanks of southern Nepal.

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In Africa, elephants  similarly have become crucial partners for acacias.

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That may seem surprising, for they are only too obviously great destroyers of acacias.

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For when other food is short, they will use their great strength

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to knock the trees down to eat their branches.

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But without elephants, some species of acacia would barely survive.

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Lots of animals come to feed on acacias.

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Inside the pods, the seeds are threatened

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by serious enemies. These beetle grubs hatched from eggs

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injected into the pods.

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They will now eat all the seeds unless they are stopped.

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Monkeys eat pods, seeds and grubs chewing it all thoroughly.

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The acacia gets little benefit from providing THEM with meals.

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But elephants are different.

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They greatly relish the seed pods which are highly nutritious.

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They go to considerable trouble

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to pick up these fiddly little things.

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But they don't grind up their food into such a fine mash as monkeys do.

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And having fed, they move on.

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They may walk for several miles before, having digested their meals, getting rid of the remains.

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These acacia seeds, 

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have spent at least 24 hours inside an elephant's stomach.

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This has killed stone dead those beetle grubs.

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The elephant's digestive juices have disinfected these seeds

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just as efficiently as a farmer dressing his seeds with insecticides.

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Ninety percent of acacia seeds in elephant dung germinate.

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Those in pods that are left uneaten on the ground will be killed by beetle grubs.

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So acacia seeds eaten by an elephant have not merely been transported, but saved from near-certain death.

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Some seeds, however, are so well-protected that it seems that nothing could eat them.

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These capsules, as hard as cannon-balls,

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contain the individual seeds the nuts

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of the Brazil-nut tree. 

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Even a fall of a couple of hundred feet doesn't crack them.

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Only one animal has the equipment to open them  the agouti.

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The agouti has two pairs of front teeth that are as sharp as chisels

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and they enable it to gnaw a hole into the capsule and get at the seeds.

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But the Brazil-nut tree protects its seeds from the only animal

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that has penetrated its armour. 

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It presents it with 15 or 20 nuts far more than an individual agouti could eat in one sitting.

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And the agouti has a habit which suits the Brazil nut. It buries what it can't eat, for later.

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What it doesn't have is a perfect memory. It loses track.

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And a significant proportion of the nuts survive to sprout.

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The Alpine nutcracker  a kind of crow  is an even more obliging partner for the arolla pine.

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The bird knows exactly how to open the cones and pick out the ripe seeds.

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Each one is swallowed, but it doesn't go into the stomach. It's stored in the crop,

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while the bird tackles the next.

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Then, like the agouti, the bird hides them, one by one, as provisions for hard times.

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But, unlike the agouti, it carries the seeds away from the forest onto open ground,

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perhaps because there it can more easily memorise landmarks

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to help it find the seeds again months later.

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These places suit the young trees very well.

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One by one, the bird brings them up from its crop.

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It buries them at a depth that suits the seed.

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Then it fills in the hole to conceal its treasure.

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So the seeds of the arolla pine are carried far from the parent tree

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and planted with all the care that a human forester might give them,

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not only in high alpine meadows,

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but even high up on the mountain ridges.

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Yet some plants succeed in reaching seemingly inaccessible sites

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without the help of any animal 

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and entirely by their own exertions. 

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A crack in a wall fifty feet above the ground is not easy to reach.

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But the ivy-leaved toadflax, nonetheless, manages to get there.

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It has no suckers like Virginia creeper or clinging roots like ivy.

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Its colonies manage to advance up the wall, from crack to crack,

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in an entirely different way.

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As the petals fall off, the seeds in the capsule beneath begin to develop.

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Then the toadflax behaves in a most remarkable way.

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It finds the nearest crack and plants its seeds itself.

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So, plants manage to get their seeds

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to the best places to germinate. But what is the best time?

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These protea growing here on the southern tip of Africa

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have had their seeds inside the seed pods for several years now.

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The time to release them is about to arrive.

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The several species of protea growing here all depend upon the arrival of seasonal fires.

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The fire has killed all the adult plants on this land,

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so this is an excellent time for seeds to germinate. There are no established competitors.

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In fact, it's the ONLY time protea seeds can germinate,

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because these seed heads have to be burnt to release their seeds.

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An hour or so after scorching, the heads open.

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All around lies a rich ash,

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which makes a nutritious bed for the seeds.

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Protea seeds can remain inert and apparently lifeless for many years

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and then spring into life when conditions are right. Some will die after 2 or 3 years.

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But others are able to remain alive for astonishing periods.

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One of the most remarkable examples comes from an archaeological site here in Japan.

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Two thousand years ago a small settlement,

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with buildings like these, stood at a place called Asada.

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The people who lived here in such houses

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had only just begun to master the art of working metal. They also knew how to plant rice.

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They stored their harvest in small pits.

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In one of those pits they found some seeds, like these.

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These are rice grains obviously dead.

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But this is a magnolia seed.

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Scientists took away that strange, ancient seed, planted it and it grew.

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At first it looked like Magnolia kobus, the wild species that still grows in Japanese woods.

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Then, in its tenth year, 

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it produced its first flower buds. These, when they opened, would reveal exactly what it was.

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Magnolia kobus today, typically, has six petals on its flowers.

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But this flower has an extra petal seven.

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And this has eight.

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Is this a consequence of its long sleep, or were all Magnolia kobus 2,000 years ago variable like this?

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Or could it be that this is an ancient species

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that has survived as that one lone seed?

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It's too early to know the answer to those questions,

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but this is surely a marvellous example of the fact that plant seeds

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are not only extraordinary travellers in space, but incomparable travellers in time.

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Subtitles by Wilma Campbell BBC Scotland 1995