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Learn about pollen

Don’t be a Pollen-hater, love the Pollinators

Illustration of a hand holding a flower with a tree branch behind it

Hay fever, or seasonal allergies, can be annoying for anyone. Sneezing, itchy, watery eyes, and a scratchy throat are all common in the spring for those suffering with allergies. Much of this is triggered by a small substance known as pollen. Pollen isn’t all bad. Despite it’s bad reputation, it’s actually very important for the environment.


Bees and flowers- a love story

Every spring, flowers seem to pop up everywhere. These flowers have an important function for the plants: reproduction. The flowers also play a key role in our ecosystem, providing insects, like bees, a tasty snack

Bees fly around from flower to flower. They eat sugary nectar made by plants in the flowers, while collecting pollen to bring back to their hive for food. At the same time, small pollen grains get stuck to hairs on the bees’ legs. The bees then carry this pollen to the next flower. This spreading of pollen helps to fertilize the next flower.

Illustration of a magnifying glass zooming in on a pollen grain on a flower


What is pollen?

Pollen grains are extremely small, up to 10 times smaller than a single grain of sand. Each flower can make a lot of pollen, and plants often have many flowers.

Pollen is the male fertilizing agent of flowering plants, including some trees, grasses and weeds. Flowers have both male and female parts, which, when combined, can develop into seeds. Pollen, created in the male part of the flower (the stamen), must be moved to the female part of the plant (the pistil), for this to happen. Pollen travels from the anther to the stigma, the top of the female flower, and then moves all the way to the ovary. Here the seed can develop. Seeds can then develop into a new plant.


What is pollination?

Pollination is the process of transferring pollen from one flower part to another.

Flowers inside illustration

It is important for helping plants spread out both geographically and genetically. The farther the pollen grains travel and to the more genetically different plants, the greater chance the species will survive overall.

There are over 350,000 different types of flowering plants! Different plants have different types of flowers. This means they also have different types of pollen, which can be moved in different ways.


Planes, trains and automobiles

Just as humans have different ways to travel, so do pollen grains. Pollen not only hitches a ride on bees, but also other insects and even larger animals like bats or hummingbirds. Wind and water can also help carry pollen grains around. Pollen can be moved from plant to plant, flower to flower, or even between two different parts of the same flower.

How pollen moves is often related to the type of flower and where the pollen needs to go for reproduction. Some flowers have both male and female parts within the same flower, and some can pollinate themselves. However, around 6% of plants have the male and female parts of the flower on separate plants. This means that some pollen has to travel far to reach its destination. Under certain weather conditions, some pollen grains can even travel hundreds of miles!

Plants that rely on wind pollination, like birch trees, are generally more responsible for allergies. This is in part because they have to produce much more pollen, to increase the likelihood a male pollen grain reaches a female flower. A single birch tree can produce up to 5 million pollen grains, and research has shown that it can travel up to 10 miles from the parent tree.

Wind pollination illustration

Pollen is important for making food for humans, insects and animals.

Once the small pollen grains reach the pistil, they can fertilize the flower, allowing the plant to create a seed. This seed can then grow into a whole new plant. Seeds are all around us and come in many types of packages. Some of your favorite foods are likely seeds of plant parts that protect the seed to help it to grow. Nuts, such as almonds and cashews, are seeds. So are all the small dots on strawberries and the pit in the middle of peaches. Even flour used to make bread comes from the seeds of wheat plants.

Pollen and allergies

For some people, when they smell the flowers, they start to sneeze. This is because they are allergic to the pollen the plant is producing. Pollen plays an important role in seasonal allergies. Although it is often called hay fever, it’s not just hay that can make people sneezy (and you won’t actually get a fever). By knowing if you are sensitive to specific plants, you can avoid plants that make you extra itchy or sneezy.

Pollen allergy illustration of a sneezing girl

When the wind blows, the pollen can be swept away from the flowers and into the air where we can breathe it into our lungs. Plants will flower (and release their pollen) at different times of the year. This means allergies might be better or worse during different seasons.

Pollen allergies are very common. Almost 10% of children in the US are allergic to pollen and, across the world, 10-30% of people may suffer from allergies. Pollen counts are useful for helping people with allergies know what to expect when they spend time outside.

Impact of climate change

Carbon dioxide and other greenhouse gases help trap heat in the atmosphere. As humans released more of these gases, the Earth’s temperature increased. This led to increasing global average temperature known as global warming. We now also see more extreme weather events and changes to global climates. Climate change and increased CO2 levels make certain plants, like ragweed, produce more pollen grains. Plants are also producing pollen for a longer period of time. And, each pollen grain has higher amounts of the part of the pollen that makes people sneeze.

This is just one of many examples of how humans have impacted the environment and disrupted the balance of cycles in their ecosystems. Learning more and understanding our role in protecting the ecosystem is one way you can help fight climate change.

Drawing of clouds

What is an ecosystem?

An ecosystem is the interacting, coexisting community of living and nonliving things in a specific area.

This includes everything from microscopic organisms to rocks to humans. It also includes factors, like temperature and humidity, which impact the organisms in the system. There are ecosystems all around us. An example of an ecosystem could be a city park. Although we don’t always think about the environment in urban areas, a park is an oasis of biodiversity, providing important habitat for many organisms.

Everything in an ecosystem plays an important role. And there are many dynamic systems that coexist in the ecosystem. One example is the carbon cycle.

Another example is the nitrogen cycle.

Nitrogen gas makes up the largest part of the air we breathe. It is also important for plant growth. But, most plants can’t absorb nitrogen from the air. Microbes that live in the soil can change nitrogen from the atmosphere into compounds like ammonia, which is also found in man-made fertilizers. Plants can use this form of nitrogen and it is important for growth. Ecosystems cycle compounds like nitrogen and carbon; however , it is important to keep these systems in balance. Too much of some forms of these elements can be harmful to the environment if they end up in the wrong place. For example, if a farmer uses too much fertilizer, it could runoff into nearby waterways, like oceans and lakes. And this can be bad for the fish that live there.

Want to learn more about what is in the air we breathe?

Read about outdoor air and pollution here

Key words about pollen

  • Pollination: the process of transferring pollen from the male part of the plant, the stamen, to the female part of the plant, the pistil.
  • Pollen: a powdery substance produced by some plants that contains many small pollen grains, which are a key component of the male plant reproductive system
  • Ecosystem: the interconnected living and nonliving things in a given area. Ecosystems also include factors, such as weather, that can impact organisms and landscapes.
  • Nectar: a sugar syrup that is made by plants to attract insects or birds to help in pollination
  • Climate change: the trend in changes to global climate patterns; this includes changes to the amount of rain, heat, and storms across the world
Sources
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