Most known flowers are usually beautiful and brightly coloured : this is because, since plants don't move, they have to attract insects (like bees, or butterflies, so they carry their pollen for them ; some other kinds of flowers don't use insects, but wind, and are less coloured, because wind don't need to be attracted !
A flower is usually compound of the following elements :
- sepals, wich are usually green, leaf-like elements, at the base of the flower. Some flowers have coloured sepals, that can play the same role as petal
- petals are big, leaf-like, coloured elements. Petals are very important in flowers that have to attract insects. They play about the same role as the "flag" for the flower, indicating the insect here it can find the flower. Petals are made to be seen from far away.
- stamina : the stamen is the organ that produce the pollen, that contains the male reproductive cell. A flower has various stamina, disposed as a crown.
- pistil is the female organ of the flower. It contains the ovary, that will become a seed after fertilisation by the pollen.
Pistil is placed at the center of the flower, surrounded by stamina, that are surrounded by petals, that are surrounded by sepals. This general pattern may vary from one flower to another.
Flowers fertilisation[edit | edit source]
In order to become a seed, the ovary in the pistil has to be fertilized by a grain of pollen. If so, the ovary turn to a seed, while the pistil (that contains the ovary) will become a fruit, that will contains the seed.
This means that pollen has to arrive from a stamen to the pistil. Moreover, in many plants, this can't be a pollen grain from the same flower, it has to be from a different one ! Problem is that plants (and, thus, flowers) don't move : they have to "find" a way to have their pollen carried from the stamina to the pistil. Many ways exist, that lead to different kinds of flowers organisations :
- In some plants, pollen is carried by insects, such as bees, bumblebees, butterflies... The insect, that eats the pollen, try to gather as many as it can from a flower, then it travels to another to go again. Since pistil is close to stamina, the insect has to rub the pistil when it is working, and drops of a few pollen grains on the pistil. Some peculiar plants are not pollinated by insects, but by other animals, such as hummingbirds, or even bats !
- In other plants, pollen is carried by the wind : these plants have very light pollen grains, that can be taken of by the wind.
- Water plants, that blooms under water (such as Neptune grass) have pollen carried by the water. In such plants, the pistil is placed well above the stamina, so the pollen grains can float to it.
Most flowers have both male (stamina) and female (pistil) organs, they are called hermaphrodite ; but some plants bear two kinds of different flowers, male ones, with only stamina (and no pistil), and female ones, with only pistil (and no stamina).
Some plants even bear only one kind (either male or female) of flowers : there are then male and female flowers, and both are then needed to have fertilisation.
Bees are not the only one to visit flowers... This butterfly, a red admiral, a much to do, with foraging each of these flowers with its long proboscis, to get the drop of nectar that is laid inside. While doing this, it covers itself with pollen that it will cary to the next flower. This plant attracts so many butterflies, as the red admiral, with its exquisite flowers, that it is called a butterfly bush.
as its name indicates, the bee orchid's flower looks like a bee. More accurately, a female bee, and it even smells like one. Whenever a male bee sees it and try to copulate with it, it covers itself with pollen, that it will carry to the next flower it will visit.]]
Different kinds of flowers[edit | edit source]
Depending on the way they are pollinated, many kinds of flowers can exist :
Flowers pollinated by insects (or other animals) have to be found by the animal from far away : they exhibit bright colours : most often, the petals are big, and full of colours, but, in some cases, this is the sepals that are coloured, or even both, as in tulips : in this case, in it almost impossible to see difference between petals and sepals, except by examinating wich ones is placed around the others : both petals and sepals are then called tepals.
To attract insects, these flowers don't have only the vision : petals are not only big, and coloured, they also produce a sweet, sugared, liquid, called nectar, and emit fragrance. This is why flowers usually smell good.
Some rare orchid flowers are pollinated by bats, that use echolocation to get its bearing ; this flowers have special shaped petals, that reverberate the sounds emit by the bat, so the flower "indicates" its position to the bat by the sound !
In the other hand, the flowers that are pollinated by the wind don't need to have big petals to be seen from far away, since the wind don't see ; furthermore, such kinds of petals would in fact be disability, by stopping the wind. Flowers that are pollinated by the wind usually have greenish, short petals and sepals,or even no petals at all. They are usually less "beautifull" (because less coloured). They have long stamina and pistil that swing in the wind.
This tulip is brighly coloured, but will you be able to see the difference between petals (inner) and sepals (outer) ? They're so similar that in this case both are called "tepals".
the bougainvillea flowers are tiny and white, but they are surrounded by great, brightly coloured, pinkish or purple leaves, to make sure the insects won't miss it.
the barren bromegrass flowers are pollinated by the wind. They are greenish, with no petals nor sepals, and very long stamina and pistil.
Did you know... ?
| the flower that smells like rotten meat
Flowers are usually beautiful and smell good... But don't forget that this is only by "accident", since plants don't try to please us, but rather the bees and butterflies that pollinate them. Luckily, it seems that what a bee or a butterfly like, in terms of fragance and colour, we like to...
Problem is, not all flowers are pollinated by bees or butterflies... The rare flower Rafflesia arnoldi, that only thrives in the islands of Java and Sumatra, in Indonesia, is pollinated by flies, and so it try to please them, in order to attract them... This is why it is all warty, dark reddish coloured, and stincks a foul odour of rotten meat... The stench is so strong, that flies come from far away, attracted by the flower, and can carry the pollen from one flower to another.
This really strange flower also holds a record : its is the biggest, and heaviest flower in the World.
Inflorescence[edit | edit source]
While many flowers use to have only one flower, at the edge of the stem, many other have various ones, arranged in a special pattern called an inflorescence. While some plants have big flowers, others have smaller ones, gathered to be seen easily from a distance. In some case, inflorescence might be very complex. Some inflorescences look like a single flower, when seen from far away.
Flowers in culture[edit | edit source]
In human culture, flower are one of the symbol of beauty. Interestingly, almost every human culture on Earth consider flowers as beautiful. Flowers are picked, and gathered to make a bunch, called a bouquet. Men often offer bunches to ladies, that keep it in a vase.
In many occasions, bunches play a special role. For example, the wedding bouquet, that is tossed during the celebration.