Flowers At Work (1956)

[Music] most beautiful event in the life of a plant is the opening of its flowers here we are seeing the growth of several tulips speeded up by the use of the time-lapse camera flowers contain the reproductive organs of our more highly developed plants and are very important flowers produce seeds and seeds in turn develop into new plants the Tulip forms a bud which develops into the mature flower seen here inside its cuplike structure are the male parts and female parts flowers that contain both male and female parts are called perfect flowers these are the stamans the male organs of the flower this is the pistol the female organ of the flower together these are the essential parts of the flour because in order to produce seeds pollen from a staman must reach the pistol this tulip has been cut lengthwise to show its structure the pedals are these conspicuous colored Parts these ends of the stamans are called anthers anthers contain pollen the pistol consists of the stigma the style and the ovary inside the ovary are ovules containing eggs when fertilized by pollen these eggs develop into mature seeds pollination takes place in two ways by self pollination and by cross-pollination here we'll watch self-pollination as shown by animated drawings when pollen grains land on the sticky stigma of the pistol they send tubes down the style to the ovary which contains the ovules the pollen tubes bearing male cells enter the ovules and fertilization takes place with fertilization complete the flow Withers and dies but the fruit continues to develop its bundle of seeds each containing a tiny new plant with the aid of the time-lapse camera we can now actually watch pollination in a tulip here the anthers split and twist and some of the pollen reaches the pistol this process is called self-pollination because pollen from the stamin of the flower is caught by its own pistol most plants including the pines and other conifers are cross-pollinated these most ancient seed seed bearing plants have small cones instead of true flowers here is a cluster of the male cones of a pine tree each tiny sack is packed with pollen which is discharged when the cone is Disturbed these cones depend on the wind for pollination wind pollinated plants must produce large quantities of pollen since much of it is blown away and wasted when a branch is Jarred or the wind strikes it the pollen stream beams out like Yellow Smoke and drifts through the air some of this pollen May reach the female cones this transfer of pollen from the stamans of one flow to the ovules of a different flow is called cross-pollination it will take 2 years for these pollinated female cones to become full-sized and mature the structure of flowers varies and so do the methods of pollination in certain varieties of the Lily the pollin is incapable of fertilizing the ovules in the same flower Snapdragon holds its petals tightly closed and only the larger and stronger insects can gain access its structure also protects the pollen from the weather color and fragrance are usually associated with flowers that depend on insect pollination in this Iris the petals are marked by brightly colored lines which lead toward the nectar cups hidden deep within the flower the sticky surface of the stigma is on the upper side when a bee enters the stigma curls under and scrapes off pollen carried on her back from some other Iris since the bee during a single day seldom visits more than one kind of flower this ensures cross-pollination inside the flower a bee's back pushes against the anther and collects fresh pollen when she backs out the stigma is pressed upward and the already pollinated surface is prevented from receiving pollen from its own stamans the visits of insects to flowers are important both to insect and flow the flow gives up its sweet nectar to the insect for food while the insect carries away pollen useful in cross pollination other methods for the transfer of pollen are also interesting in the poor man's Orchid shown here as a drawing the lower petals cover the anthers when the petals are depressed the pollen is shot forth by the Catapult action of the anthers this drawing of a meadow Sage flower shows how its Stam are constructed like a swinging lever when the bee seeks nectar it presses against the lever the anther strikes the body of the bee and deposits pollen flowers of the milkweed have a perfume which attracts insects as the flowers pop open one at a time they send out this strong sweet odor a clearwing moth is an eager visitor it hovers over the flowers and sips nectar in contrast bumblebees like to land on the flower this one seems to be in trouble it's caught by one foot now the Bumblebee breaks away to see what happened here is a single flow of the milkweed between each pair of nectar cups is a slit the slit leads to a grooved black knob at the top the grooved knob is attached by slender threads to a hidden pair of pollen bodies in slow motion we see how the trapped foot of the bee pulls out the pollen bodies these pollen bodies may be caught by the next flower visited by the bee and a new pair carried away here on just one foot of a bee are 15 pollen knobs and several pollen bodies not yet caught you might like to try to duplicate the delicate action of the bee's foot with the aid of a bent pin it is difficult enough to get the pollen bodies out to say nothing of drawing them into the tiny slit of another flower this trapping of the insect's foot is a good example of the many ways in which flower parts and insects are adapted to help each other the bachelor button or cornflour is a composite belonging to one of the largest families among the flowering plants the composits are characterized by the grouping of many small flowers in a single head the dandelion is a member of the composite family it has about 100 tiny flowers packed tightly together to form a single head as the morning sun strikes it the closed head begins to open the opening takes only about 15 minutes the flowers toward the outside of the head develop first those at the center come out the next day this helps prevent self-pollination as the pistols emerge from the anther tubes they lift the pollen and expose it on the outer surfaces of strap-like bodies where it may be carried away by insects later the stigmas separate and their receptive inner surfaces can accept pollen from another flower at the end of the day the entire head of flowers closes next morning if pollen has not yet been received from another flower the stigmas curl so far around that they pick up pollen from their own Styles thus self-pollination may serve as a last resort when cross-pollination has not occurred so in two short days each head with its hundred or more separate flowers fulfills its Destiny it closes to develop seeds today the growing of flowers is more than a billion doll industry employing scientists and other workers who are constantly striving to improve coloring and fragrance of flowers through the development of new varieties of all the flowers that man has cultivated and improved perhaps none is more beautiful than the [Music] rose we have seen how pollen from a flower can self-pollinate the same flower we have watched bees and other insects carry pollen from flower to flower and I've seen the wind Aid in the same process called cross-pollination we must rely on the processes of pollination for much of our food as in flowering plants of corn and rye and for much of the beauty in our world for it is from flowers that seeds are produced and from seeds new plants develop from generation to generation oh [Music]