U.S. Forest Service
United States Department of Agriculture
What is Pollination?
Pollination is the act of transferring pollen grains from the male anther of a flower to the female stigma. The goal of every living organism, including plants, is to create offspring for the next generation. One of the ways that plants can produce offspring is by making seeds. Seeds contain the genetic information to produce a new plant.
Flowers are the tools that plants use to make their seeds. The basic parts of the flower are shown in the diagram below.
Seeds can only be produced when pollen is transferred between flowers of the same species. A species is defined a population of individuals capable of interbreeding freely with one another but because of geographic, reproductive, or other barriers, they do not interbreed with members of other species.
Parts of a flower.
This wasp is a specialist pollinator of Penstemon, which is the flower it is visiting, or rather sleeping in here. Photo by Dr. Jim Cane, USDA ARS Bee Biology and Systematics Laboratory, Logan, Utah.
How does pollen get from one flower to another? Flowers must rely on vectors to move pollen. These vectors can include wind, water, birds, insects, butterflies, bats, and other animals that visit flowers. We call animals or insects that transfer pollen from plant to plant “pollinators”.
Pollination is usually the unintended consequence of an animal’s activity on a flower. The pollinator is often eating or collecting pollen for its protein and other nutritional characteristics or it is sipping nectar from the flower when pollen grains attach themselves to the animal’s body. When the animal visits another flower for the same reason, pollen can fall off onto the flower’s stigma and may result in successful reproduction of the flower.
Referring to the animated image, pollen from the anthers of Flower 1 is deposited on the stigma of Flower 2. 0nce on the stigma, pollen may “germinate,” which means that a “pollen tube” forms on the sticky surface of the stigma and grows down into the ovule of the plant.
This growth can result in:
- Successful fertilization of the flower and the growth of seeds and fruit; or,
- A plant can be only partially fertilized, in which the fruit and/or seeds do not fully develop; or,
- The plant can completely fail to be pollinated, and may not reproduce at all.
- Self-pollinating – the plant can fertilize itself; or,
- Cross-pollinating – the plant needs a vector (a pollinator or the wind) to get the pollen to another flower of the same species.
U.S. Forest Service United States Department of Agriculture What is Pollination? Pollination is the act of transferring pollen grains from the male anther of a flower to the female
What Is Pollen: How Does Pollination Work
As anyone with allergies knows, pollen is abundant in the spring. Plants seem to give off a thorough dusting of this powdery substance that causes so many people miserable symptoms. But what is pollen? And why do plants produce it? Here’s a little pollen information for you to satisfy your curiosity.
What is Pollen?
Pollen is a small grain made up of just a few cells and is produced by both flowering plants and cone-bearing plants, known as angiosperms and gymnosperms. If you are allergic, you feel the presence of pollen in the spring. If not, you likely notice it dusting surfaces, often giving things, like your car, a greenish tinge.
Pollen grains are unique to the plants they come from and can be identified under a microscope by shape, size, and the presence of surface textures.
Why Do Plants Produce Pollen?
In order to reproduce, plants need to be pollinated, and this is the reason that they produce pollen. Without pollination, plants will not produce seeds or fruit, and the next generation of plants. For us humans, pollination is so important because it is how food is produced. Without it, our plants wouldn’t make the produce that we eat.
How Does Pollination Work?
Pollination is the process of moving the pollen from the male components of a plant or flower to the female parts. This fertilizes the female reproductive cells so that a fruit or seeds will develop. Pollen is produced in flowers in the stamens and then must be transferred to the pistil, the female reproductive organ.
Pollination may occur within the same flower, which is called self-pollination. Cross-pollination, from one flower to another, is better and produces stronger plants, but it is more difficult. Plants have to rely on wind and animals to transfer pollen from one to another. Animals like bees and hummingbirds that make this transfer, are called pollinators.
Pollen in the Garden and Allergies
If you are a gardener and a pollen allergy sufferer, you really pay the price for your hobby in the spring. Pollen and pollination are essential, so you want to encourage it, yet you want to avoid allergy symptoms.
Stay inside on high-pollen days and days that are windy in the spring, and use a paper mask when in the garden. Put your hair up and under a hat, as pollen can get trapped in it and come in the house with you. It’s also important to change your clothes after gardening to stop pollen from coming inside.
As anyone with allergies knows, pollen is abundant in the spring. Plants seem to give off a thorough dusting of this powdery substance. But what is pollen exactly? And why do plants produce it? Here's a little pollen information for you to satisfy your curiosity.