Have you ever watched plants grow, flower, disappear, and then seen new ones spring up and grow in their place? If you have, then you have seen a plant’s life cycle go full circle.
Want to know more about a plant’s life cycle? Keep reading, and we will explain the life cycle of plants and throw in some fun facts for free.
What is a Plant Life Cycle?
All living things have a life cycle.
A life cycle is all the stages that make up the life of a plant or animal. From the time they first enter the world till they die.
In flowering plants, this begins when they first emerge from seeds and continues until they produce seeds of their own, completing the circle of life.
Most plants you are familiar with, flowers, trees, bushes, and grasses, follow this same life cycle.
There are plants, though, that don’t produce seeds. Their life cycle is slightly different, and we will talk about seedless plants more at the end of this article.
For now, let’s focus on the life cycle of flowering plants.
Different Stages of a Plant Life Cycle
There are six stages to the plant life cycle. Let’s take a look at each one.
A seed is like a baby plant waiting to be born. Only, unlike an animal baby, it is entirely self-contained. You could think of a seed as being asleep (dormant) and waiting for the right conditions to wake up and spring to life. Some seeds can rest like this for hundreds or even thousands of years.
A seed consists of three parts:
- Seed coat– The seed coat is the hard outer shell that protects the baby plant inside. It also senses when it is time to let the plant start to grow.
- Embryo– The embryo is the actual baby plant. Though tiny, it contains all the parts that it needs to grow into an adult.
- Endosperm– Endosperm is a fancy way of saying food supply. This is the biggest part of the seed, and its job is to supply the energy the baby plant (embryo) needs to push its roots into the soil and first leaves into the sun.
All flowering plants begin as seeds, and it is only when they have the correct amount of water, the right temperature (warmth), and good soil to grow in that they move to the next stage of their life cycle.
When a seed feels the conditions are right, it will sprout. Sprout means it will wake up and start trying to grow. A seed that has sprouted is said to have germinated or entered the germination phase of its lifecycle.
First, the seed coat will split open, and a tiny root will emerge, growing down into the soil. The seed can be turned in any direction, but the root will always dig deeper into the ground. Scientists aren’t sure how the plants know up from down, but they do.
Small hairs, too tiny to see (microscopic), will branch out into the surrounding soil from this root. Their job is to take in (absorb) from the ground, water, and minerals the plant needs to grow.
Soon after the first roots appear, a tiny stem will start pushing its way toward the surface. As this stalk grows towards the waiting sunlight, it will carry one or two seed leaves tightly curled around it to the surface.
When the tiny stem finally breaks through the soil’s surface and reaches sunlight, the little seed leaves will spread out. Once these leaves have uncurled, the plant is said to have completely sprouted or fully germinated.
The seed leaves begin taking in energy from the sun and, using photosynthesis, produce food for the plant to continue growing. Plants are the most independent living things on our planet. They don’t have to eat. They take in water and minerals from the soil, gases from the air, and with the help of energy from the sun, produce their own food.
Soon after the seed leaves begin their work, the first true leaves will start to grow. Once these adult leaves develop, the plant is no longer a sprout. It has now become a seedling and entered the next phase of its life cycle.
A seedling is much like you are now. You are no longer a baby (sprout), but you haven’t become an adult (mature plant) yet.
The seedling phase of the life cycle is where the fastest growth and biggest changes occur. The plant is getting bigger. Its roots, stems, and leaves are growing larger and stronger. It is preparing to become an adult plant.
4. Adult Plant
An adult (mature) plant has a stem, leaves, roots, and flowers. Flowers are the part of the plant that produces new seeds.
The main parts of a flower are:
- Petals- The bright part of the flower that attracts pollinators (insects).
- Sepals- The firm section around the bottom of the flower that provides support for the rest.
- Stamen- Male organs
- Pistil- Female organs
Some adult plants have what is called perfect or complete flowers. This means that they have all four of the parts listed above. A Rose is an example of a plant with complete flowers.
Other plants such as begonias and gourds have incomplete flowers. This means one or more of the parts are missing. In most cases, the missing part will be the Stamen (male organ) or Pistil (female organ).
If the stamen is missing, the flower is female and called a pistillate. If the pistil is missing, the flower is male and called a staminate.
Plants having complete or incomplete flowers will be discussed further in the next section.
When a plant is in the adult phase of its life cycle, it is ready to reproduce (make new seeds) and has almost completed its life cycle. There are just two steps left.
The next stage of a plant’s life cycle is called pollination. Pollination is when pollen moves from the male stamen to the female pistil and leads to the creation of seeds in the plant.
In most plants and all plants that have incomplete flowers, this requires the help of what are called pollinators. Pollinators are all the bees, beetles, ants, butterflies, and other insects you see moving from flower to flower.
Pollinators are attracted to the flower’s bright colors and sweet smells and visit them looking for a snack. When a pollinator’s body brushes against the male stamen, it picks up pollen. Then when it visits a female flower, the pistil removes the pollen.
This is how pollination occurs in most plants, but some, including many of those with complete or perfect flowers, don’t need help from pollinators. They are called self-pollinators. A slight breeze or gentle shaking is all that is necessary for them to move pollen from the stamen to the pistil.
Once pollination has occurred, seeds will begin to grow.
6. Seed Dispersal
The final stage in the plant life cycle is the dispersing (spreading) of their mature seeds. Nature has found many ways for plants to spread their seeds, including:
- Plants like the dandelion allow their seeds to float on the wind.
- The sycamore tree has wings attached to its seeds, and they fly away.
- Coconut trees and lotus flowers have seeds that float on water and get carried away by rivers and oceans.
- Many plant seeds have small hooks on their skins that grab onto passing animals and people’s clothes, then get dropped in new locations.
- Most fruit and berry-bearing plants rely on their seeds being eaten and getting spread when animals poop them out.
- Squirrels and other rodents often collect and bury seeds to feed on in the winter but often forget where they buried them. They spread plant seeds.
- Some plants like ginseng and balsam trees have seed pods that explode, slinging their seeds over a wide area.
Once a plant has dispersed (spread) its seeds, the plant life cycle is complete and ready to begin again.
What is the Plant Life Cycle Called?
The plant life cycle is called a haplodiplontic life cycle.
Plant Life Cycle Video
Plant Life Cycle Diagram
What Are Seedless Plants?
Seedless plants are types of plants that do not produce flowers and so cannot make seeds. Instead, they reproduce using special structures called spores or by simply spreading. Scientists believe that they have been growing on our planet for over 400 million years.
Are Spores the Same as Seeds?
Spores are much like seeds. They can lay dormant (sleep) for long periods. Some are so small and light they can float in the air or water. New plants grow from them, and they will only start to grow when conditions are right.
What makes spores different is that they grow from a single parent (asexually). Seeds are produced by male and female parts of the plant coming together. This is called sexual reproduction.
Types of Seedless Plants
There are four different types of seedless plants divided into two distinct groups; vascular and non-vascular. Vascular seedless plants have tube structures that carry water and food throughout the plant, and they have proper roots, stems, and leaves. Non-vascular plants are missing all of these features.
10 Interesting Facts About the Life Cycle of Plants
- When the seed pod of the dynamite tree pops, it can throw seeds over 100 feet.
- The seed of the Coco de Mer (sea coconut) is the world’s largest seed and can weigh over 80 pounds
- In the tomb of King Tutankhamun, archeologists found jars of seeds over 3,000 years old, and scientists were able to sprout them.
- Honey produced by bees from the pollen of plants never spoils or rots and can be eaten thousands of years after jarred.
- 85% of all plants live in the ocean.
- The fruit of an apple tree is 25% air and will float.
- The seed of the dandelion can float for over five miles.
- The Pando tree can resprout from its roots, and one tree in the Fishlake National Forest, Colorado, covers over 108 acres.
- A Coastal Red Wood named Hyperion is 379.7 feet tall, 600 years old, and is in the “Guinness Book of World Records.”
- Strawberries are the only plants that have their seeds on the outside of their fruit.