Pollination: a brief explanation of the different species

The pollination of different plants can work very differently - as wind pollination or insect pollination, for example. You can also find out what foreign and self-pollination is all about here.

How was that again with the bees and the flowers? Many people have long since forgotten their biology lessons at school and do not know how plants actually reproduce. So here comes the little, innocent explanation about wind pollinators, animal flowering, self- and cross-pollination. Because the plants love each other in very diverse ways.

What is pollination?

The process of transferring pollen to the stigma or ovule is called pollination. Here, as in humans, two halved genes come very close: One is in the male pollen, one in the female ovary. If everything goes well, the pollen germinates, grows through the style of the flower with its pollen tube over several days and finally reaches the so-called embryo sac cell. This is where the two cells fuse and the genetic material they contain is combined.

What types of pollination are there?

There are two possible answers to the question of which pollen can be used to fertilize a plant: self-pollination and cross-pollination.

Self-pollination

In self-pollinators, the union of ovaries and pollen from the same plant can lead to ovules. This has the advantage that a few individuals can quickly become a whole colony. Pioneer plants are therefore often self-pollinators.
Examples of self-pollination: Little snowdrop (Galanthus nivalis), Barley (Hordeum vulgare), Beans (Phaseolus vulgaris), peas (Pisum sativum)

Cross-pollination

Cross-pollinators cannot fertilize themselves: pollen and ovaries must come from different individuals of the same species in order for fertilization to take place. This has the advantage that the genetic variability and thus the adaptability of these plants is very high.
Examples of cross-pollination: Primroses (Primula), Purple loosestrife (Lythrum salicaria), Sorrel family (Oxalidaceae), Irises (iris), sage (Salvia), Corn (Zea mays)

Some plants tend to self-pollinate, others to cross-pollination - some can do both equally. Cross-pollination is, however, the far more common case. Incidentally, whether a plant is a self-pollinator or a cross-pollinator says nothing about whether it is from Insects, the wind, bats, birds or even water being pollinated: all combinations are possible. Most plants are very effective in preventing self-pollination. Because cross-pollinators have the advantage that the sexual recombination with the genome of another plant results in a profitable mixing of the properties. This may enable the offspring of the plants to adapt to new environmental conditions.

Expert tip: The fact that a plant does not fertilize itself is determined by various mechanisms in nature guaranteed: approximately different flowering times for male and female flowers on a plant, as with the hazelnut (Corylus avellana). Or the flowers of different individuals are structured in such a way that a pollinating insect always first strips off the pollen from another plant on the stigma before it gets to the pollen. Enzymatic self-sterility is also possible: this either prevents the pollen from germinating or the pollen tube is stopped in the stylus by specialized enzymes before it hits the ovary achieved.

Insect pollination

Many plants rely on insects for pollination. This is also called "insect bloom". The term becomes understandable if you look at the flowers of these plants: all from insects Pollinated plants have brightly colored, highly fragrant or otherwise insectic attractive flowers. Incidentally, many plants specialize in "their" pollinators - and the other way round the same applies: flower shape and depth, Nectar composition, altitude and distance of the insects, time of flowering and hatching of the insect larvae are precise Voted. the Bee pollination is certainly known to everyone. But also Butterflies, Flies, moths and many others are important pollinators. These small beneficial insects can with insect-friendly seed mixtures like the Plantura bee pasture, to the Plantura butterfly meeting or that Plantura beneficial insect magnets get supported.
Examples of insect pollination: Fruit trees like Apple (Malus), Pear (Pyrus) and cherry (Prunus), Lumpwort (Pulmonaria), Arum (Arum), Linden trees (Tilia), Chestnuts (Aesculus), Meadow clover (Trifolium pratense).

Wind pollination

Wind pollination on plants is seen as the original form of pollination. In primeval forests, pollen was only carried from plant to plant with the wind. You can recognize wind pollinators by their long, hanging kittens. The pollen dusts out of it in the wind and gets to the inconspicuous female flowers. These are not noticeable at first glance: Often only so-called scar branches are formed on which the pollen can land. There are no petals or similar ornaments.
Examples of wind pollination: hazelnut (Corylus avellana), Willows (Salix), Alder (Alnus), Birch trees (Betula)

More information about the Pollination by bees can be found in our special article.