Pollen

Pollen is a powdery substance made by most flowers of seed plants. It helps plants make new plants.

Pollen grains have a strong outer coating. This protects them as they move from one part of the flower to another. If a pollen grain lands in the right place, it grows a tube. This tube carries the male cells to meet the female cells. This lets the plant make seeds.

The study of pollen is called palynology. It helps scientists learn about the past, study old plants, and even solve crimes. Pollen can also be used as a food supplement.

Structure and formation

Pollen is a special dust made by flowers and some plants. It helps carry a tiny part of the plant. Each pollen grain has cells that help it move and a cell that becomes part of the plant when it finds the right flower.

Pollen grains come in many shapes and sizes. Some are round, some are long, and some even have little wings. For example, pollen from pine trees has wings, while forget-me-not flowers make very tiny pollen grains. The outside of pollen is very strong, which helps protect it on its journey.

Pollination

Main article: Pollination

Pollination is when pollen grains move to the female part of a plant, called the pistil. This can happen in a few ways. One way is by wind. Plants that use wind to carry their pollen often make lots of very light pollen. These are called anemophilous plants.

Some plants need help from insects or other small creatures to move their pollen. These plants make pollen that is heavier and stickier, which attracts insects and other pollinators. These plants are called entomophilous. Many insects eat pollen and are known as palynivores.

In the fossil record

Main article: Palynology

Pollen has a special outer coating that helps it last a very long time, even when other things break down. Because of this, scientists can find pollen in old rock layers and study it. This helps them learn about plants that lived long ago and what the weather was like back then. We first see pollen in rocks from a very old time called the Devonian period, though it looked a bit different back then. Since then, we find more and more pollen.

Allergy to pollen

See also: Allergy season

Nasal allergy to pollen is called pollinosis, and allergy specifically to grass pollen is called hay fever. Pollen that causes allergies often comes from plants that spread their pollen through the wind. These plants make lots of lightweight pollen that can travel far and get into our noses.

Pollen allergies are common where the weather changes between cold and warm, but less so in very warm places. In northern Europe, birch and alder pollen often cause allergies. In the US, many think goldenrod causes allergies, but it's actually ragweed. Symptoms of pollen allergies include sneezing, a runny or itchy nose, and watery, itchy eyes. These symptoms can sometimes lead to asthma problems.

Treating pollen allergies often means avoiding pollen when possible. Medicines like antihistamines and decongestants can help with symptoms. There is also a treatment called allergy immunotherapy that helps the body get used to pollen over time.

Nutrition

Many animals eat pollen. Bees are famous for eating pollen, but other insects like spiders, beetles, and flies also eat it. Some spiders catch pollen in their webs, and some beetles eat almost only pollen. Even some tiny creatures like mites and fungi can use pollen as a food source.

People sometimes eat bee pollen as a food or supplement. It has carbohydrates and protein, but the U.S. Food and Drug Administration says there is not strong proof that it gives special health benefits. People should be careful because pollen can cause allergies or have harmful substances if not stored properly.

Forensic palynology

Main article: Forensic palynology

In science, pollen can help figure out where a person or object has been. Different places, like certain bushes or areas of the world, have their own special mix of pollen. This helps experts learn important clues. For example, pollen has been used to study places from history and help solve mysteries.

Spiritual purposes

In some Native American religions, pollen was used in prayers and rituals. It stood for life and new beginnings. Pollen helped make objects, dancing areas, paths, and sandpaintings special. Sometimes it was sprinkled on people’s heads or in their mouths. Many Navajo people believed that walking on a path with pollen made the body feel holy.

Pollen grain staining

Scientists sometimes check if pollen grains are healthy, especially for farming research. One way they do this is called Alexander's stain. This special mix of liquids shows if a pollen grain is working well. Healthy pollen grains turn red or pink, while the ones that are not working turn blue or a little green. There is also a safer version of this mix that leaves out some stronger ingredients.