Parts of a Flower and Plant and Their Functions (8 Diagrams

Buttress roots of a tree

In general, most dicot plants (peas, carrots), or two seed-leaf plants, have taproot systems while monocot plants (corn, grasses), or one seed-leaf plants, have fibrous root systems. Further comparisons between monocots and dicots are found in these tutorial guides: Fruits Flowers and Seeds & Stems.

Different forms of roots: taproot (left), fibrous (middle), modified root (right)

Roots are the portion of a plant that interface with the ground. They perform three primary functions, anchoring the plant, absorbing water/nutrients/minerals, and also act as storage of energy for future use. There are generally two types of plant roots, fibrous and tap-root.

Although mostly hidden from our view, plant roots are one of the more simple, yet fascinating parts of a plant. In this post I plant to go through a detailed explanation on plant roots and how they work – ie, what type of roots exist, what functions to the perform, how do they grow, and some other interesting facts.

Massive tap-root of a tree growing on a cliff

What types of roots exist

Fibrous Roots

Fibrous or diffuse roots are thin, somewhat stringy roots that spread around the plant, occupying a large volume of shallow soil. Fibrous roots absorb water as it infiltrates the soil, generally catching it in shallow depths. Common turf or lawn grass is an example of fibrous roots.

Tap Root

A tap root system is a thicker, sparsely branched root that grows straight down into deeper soil where it can access deep water tables and minerals. In sandy or shifting soils, tap roots do a great job anchoring the plant.

Root system of a first year Pokeweed plant (tap root)

There are some plant species that will have both fibrous and taproots. And even some plants will change their root style as they grow. For example some trees begin producing taproots such as Red & White Oak, only to change and switch to a more shallow root depth as the tree matures.

What do plant roots do?

All plant roots have three primary functions:

No matter what species of plant, the root is the part of it that will exchange water, minerals, and nutrients to support the upper portions of the plant. And storing food underground in the roots is a smart evolutionary method, as it is relatively hidden from most animals.

Anchoring the plant

Roots occupy large volumes of soil either a fibrous root system or tap-root. But, roots bond with the soil and grip, anchoring the plant from tipping over, washing or blowing away. Fibrous roots will spread out far and wide from the base of the plant, gripping hold of all the local shallow soil while helping to prevent erosion. Tap roots send on or more sparsely branched roots straight down to deeper ground, gripping the deep ground.

Absorb water and minerals

Roots support plants by absorbing water, nutrients, and minerals from the soil. As rainwater begins to percolate into the ground, fibrous roots will absorb it when needed. Where as tap roots access deeper water tables.

Store excess food for future needs

Both fibrous and tap roots are used to store food for future use. In perennials, this stored food & energy is what the plant draws on in Spring to reemerge until it can regrow leaves and restart photosynthesis.

Common root depths

Given proper soil texture and structure, even roots of annual crops can grow to incredible depths. Weaver & Bruner observed in their 1927 study that annual lettuce crops could reach depths of up to 7′ deep in a single growing season. This illustrates that even smaller crops and plants may have extensive, albeit hidden growth underground.

Surprisingly, many tree roots only occupy the top 3′ of soil. In fact if you hike in an older oak forest you may come across a tree that has tipped over. If you look at the root ball, you will clearly see that there is no taproot, only shallow woody roots. This is in contrast to most conifers (evergreens), which are firmly anchored with a tap root. Most fruit and nut trees will produce the majority of their roots in a circle, extending to the ‘drip zone’ of the canopy, which is the area where most of the rain is directed via the canopy.

How Roots Grow

Since the primary purpose of roots is to find and absorb water and minerals, that is the direction they will grow. Probing in between soil aggregates and pushing through in a never-ending quest to supply the plant with adequate moisture and nutrients.

The amount of roots that will be present at various depths and sizes will vary with the species of plant being studied, as well as the soil type, structure, and available water. Watering infrequently, but for longer durations will encourage roots to grow deeper. Grass roots (and most other plants) will grow deeper roots if they have a need to access water that is deeper in the earth. This should be done with lawns and most plants, as if they are watered frequently they may not have a reason to grow them deeper to access water tables.

This interesting root system is actually growing down into an abandoned mine. It is likely that the root continually was accessing water and minerals, and kept growing deeper.

Root Hairs and Branches

Fuzzy root hairs are what a root uses to absorb water, starting approximately 1/4″ (6 mm) from the tip of the root and going back towards the plant. These will occur radially around the root, giving it an almost ‘fur-like’ coat. These hairs are easily broken when a plant is dug up from the soil.

The root hairs are quite visible on this specimen of Fire Pink, Silene virginica

Roots will branch as they age and grow in an attempt to locate more water an nutrients in a somewhat exploratory manner. They originate from the parent root and grow at approximate right angles to it. And will continue to grow and branch in areas where they have success. So, once large enough, branches will begin to produce branches.

Are stolons, rhizomes, or suckers roots?

The rhizome (horizontal stem) from Common Milkweed. One of the more aggressive native plants, it can colonize any full sun area.

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Roots are the non-leaf part of a plant’s body that does not bear any nodes. It is the organ that lies below the surface of the soil. Roots can also be aerial i.e. growing above the surface of the ground or aerated which means floating over the surface of the water. Roots are responsible for providing the stems and the leaves with adequate water and nutrients for their growth.

Anchor and Support

The root system of the plant provides physical support by anchoring the plant body to the soil. Many plants can stand erect for hundreds of years because their roots grow deep into the soil and hold the plants strongly in place.

Absorption and Conduction

Roots have root hairs through which roots absorb water and nutrients from the soil which are essential for the plant growth. Roots have a capability of absorbing inorganic nutrients against the concentration gradient. After the water and nutrients are absorbed, they are moved upwards to stem and leaves.

In deserts, roots grow deep into the permanent water reserves. Desert areas where plants are found to be growing are considered to have underground water reserves. This greatly helps in deciding where to dig a well.

Roots have specially designed channels for the transport of absorbed nutrients and water to stem and leaves. Moreover, they also have channels through which organic food can be transported from aerial parts of the plant to the roots.

Some roots like carrots and sweet potatoes serve the purpose of a storage organ. They store carbohydrates and water. Roots of some plants found in desserts can store up to 70kg of water.

Photosynthesis is the process by which plants prepare their food. Some roots are capable of photosynthesis as is the case with aerial roots of mangrove plants and epiphytic orchids.

Plants that grow on the surface of stagnant water have specialized roots that are called pneumatophores which diffuses the oxygen from the air.

Contractile roots of many bulb-forming plants pull the plant downwards into the soil. Environment under the soil is more favorable for bulb-forming plants.

Some special roots are capable of reproduction. They serve as a means of perpetuating a species. In some plants like the mature agoho, offshoots are seen growing around the trunk profusely from roots that are growing horizontally.

Anatomy of Roots

The root has four main regions:

The root cap is present at the apex of a root. It is a thimble-like structure. The apex of a root is tender. A root cap protects this tender end and aids the root in propagating deeper into the soil.

The root cap secretes mucilage which is responsible for lubricating the passage for the root through the soil. This mucilage also aids in the absorption of water and nutrients. Root cap wears out but it is renewed constantly.

The Meristematic Region

The term meristematic means rapid growth. This region is present just above the root cap. The cells in this region grow rapidly. They are very small and extremely thin-walled. They have dense protoplasm.

The Region of Elongation

The cells in the region of elongation rapidly enlarge and elongate. The cells in this region are responsible for the growth of root length.

The Region of Maturation

The cells in the region of elongation gradually mature after differentiation and form the region of maturation. The cells differentiate to form various specialized tissues like permanent region and root hairs.

Monocot Roots and Dicot Roots

Roots of a monocotyledon plant are called monocot roots and roots of a dicotyledon plant are called dicot roots.

Monocotyledon plants have a single cotyledon in their embryo. In monocot roots, xylem and phloem are arranged in a circular manner. Dicotyledon plants have two cotyledons in their embryo. In dicot roots, xylem is present in the middle and phloem surrounds it.

Difference Between Monocot Roots and Dicot Roots

The differences between monocot roots and dicot roots are:

Monocot Root Example

The pericycle gives rise to lateral roots only. The pith is well developed and large. Numerous xylem and phloem are present in monocot roots. There is no secondary growth.

Dicot Root Example

The pericycle gives rise to several lateral roots, cork cambium, and some part of the vascular cambium. The pitch is absent. There is a limited number of xylem and phloem. Secondary growth occurs in the dicot root.

Different Types of Roots with Examples

There are different types of roots in plants depending upon the type and species of plants. The major types are:

Fibrous roots are found in monocot plants. They are slender, branched, and grow directly from the stem. These roots tend to grow close to the surface and spread horizontally.

They are characterized by a cluster-like appearance with numerous roots together, all nearly of the same size. In the fibrous root system, the primary root is short-lived. It is replaced by numerous roots.

Fibrous root system does not provide strong anchorage to the plant as they do not penetrate deep into the soil.

Taproots are found in the majority of dicot plants. This type of root is a direct elongation of the radical. Unlike fibrous roots, taproots are not branches. Instead, they are a single primary root that grows deep into the soil. A taproot gives rise to lateral branches (secondary and tertiary roots) leading to the formation of a taproot system.

The branches of a taproot grow in acropetal succession which means, the longer and older ones are present at the base while newer, shorter ones are near the apex of the primary root.

Taproot system provides a very strong anchorage. The reason for this strong support is that they penetrate deep into the soil.

In some plants, the taproot does not grow too deep. Instead, its lateral branches grow longer horizontally along the surface. These types of roots are called feeder roots.

Adventitious roots are similar to the fibrous roots. However, they can be underground or aerial (above the ground). They can grow from any part of the plant except the radical.

Usually, they grow from intermodal, stem nodes, and leaves. These roots can be thick, thin, or modified according to the species. Adventitious roots arise under stress conditions such as waterlogging after floods.

Leaf cuttings and branch cuttings in plants such as rose can result in the development of adventitious roots. They also develop in cases of plant injury. These propagative roots can increase the survival chances of a plant as the plant propagates itself with the assistance of adventitious roots.

Creeping roots are the types of roots in plants that do not penetrate deep into the soil. They are shallow and spread a long way horizontally from the base of the plant. Many trees have creeping roots.

Tuberous roots are very thick roots. They store significant amounts of food to feed the whole plant. They are a fleshy, enlarged, and modified storage organ. They are modified from the stem.

These propagative roots propagate by crown division where each crown division has several buds and sufficient storage to make a new plant.

Water roots are the types of roots that plants in water grow. They are finer and more brittle. They have a capability to allow oxygen from the atmosphere to diffuse in which is then used by the roots for metabolism and growth. They are morphologically different from soil roots.

Parasite roots are types of roots that attach themselves to the other plant and suck nutrients from it. They do not offer any benefit to the host plant. Instead, they cause serious damage, hence the name, parasite roots.

The facts about roots listed below are some amazing pointers that we are sure you have never heard of before:

Uses of Roots to Man

Roots are widely used by man. Some of the most prominent uses of roots to man are:

Important Medicines Made From Roots

As mentioned earlier, roots are a source of some very important medicines. We have listed down the most prominent ones for you.

Turmeric root is capable of treating anything from stomach pain to arthritis, to disorders of gallbladder and liver, to menstrual cramps, to infection and headaches. Turmeric is mostly used as a spice but the medicinal uses of turmeric root are just phenomenal.

Ginger is effective in cases of diarrhea, nausea and upset stomach. It can also be used for relief from cold, congestion, flu, and headaches.

Licorice has been used for ages to treat stomach ulcers, bronchitis, and sore throats. According to some studies, licorice can also be helpful in the treatment of hepatitis C.

This medicinal root can be used to treat arthritis, liver diseases, and fibromyalgia.

Valerian is used for treating sleep disorders. Many people who are struggling to get out of their habit to consume sleeping pills have benefitted from Valerian. Some studies suggest that this herb can make chronic insomniacs fall asleep more easily and quickly.

Who knew roots were such magical part of a plant? Not just they are the heart and lungs of a plant but they offer enormous benefit to humans.

How fast do roots grow?

Three weeks to a month. Creating new plants from clippings is simple, but requires extra attention to guarantee success. The time needed for a plant to generate new roots varies from species to species, but in general, it takes at least three weeks.

Why are roots important?

There are many critical roles that are played by a plant’s roots. As the plant’s roots hold it firmly in place, it is able to withstand the effects of wind, water, and muck. It is the plant’s root system’s job to draw oxygen, water, plus nutrients from the soil and then transport them to the plant’s upper parts (the stem, leaves, and flowers).

Can a plant regrow its roots?

If less than a quarter of the root zone is damaged, numerous plants may survive and regenerate. Damaged or broken roots will regenerate. Growth is stunted because water and nutrient intake are impeded. The new development, however, will not proceed in the same way.

Can bamboo roots grow through concrete?

If concrete is solid, bamboo cannot damage or grow through it. However, bamboo, if unchecked, may invade homes through any number of openings it can find.

The rhizomes of bamboo plants are capable of sending up shoots that can penetrate and destroy structures. Nevertheless, bamboo is incapable of breaking through solid concrete due to its strength.

Can you cover tree roots with dirt?

It is not recommended but if you must, only do it slightly. Yet, you should be warned about covering a tree’s roots with soil.

Lenticels, which are structures for exchanging gases, cover the roots on the surface. Trees can die if their roots are buried under too much dirt because they need oxygen to survive.

Can trees survive root damage?

Trees can survive depending on the level of damage to its root. If any significant portion of a tree’s root system gets damaged it can be catastrophically compromised.

In most cases, a tree’s health can be compromised by destroying only 20% of its root system. To cut off 40% of the tree’s root system would likely be disastrous. It’s dangerous, too, and needs to be taken out.

Do roots have chloroplasts?

No! Chloroplasts are absent from the underground organs and inner stem cells like the root system and bulb.

Chloroplasts would be ineffective in these environments since they receive no sunlight. Since their principal functions are reproduction and dispersal, the cells of fruits and flowers often lack chloroplasts.

Can roots strangle a tree?

Yes! When the roots of a tree wrap all the way around the trunk, this is known as girdling. You may say that the tree’s roots are suffocating or strangling it. Indeed, that has been found to be the case. Trees are killed when their oxygen supply is cut off by girdling roots.

Home9 Different Types of Roots Found on Trees, Plants and Flowers

Our Most Popular Herb-Growing Guides

The older I get, the more I appreciate the beauty of nature. As a kid, I was never much of a hiker, but now I love spending an hour hiking trails.

My growing love of nature extends to gardens, trees, plants and flowers. I love how you can plant seeds or buy flowers and create something so beautiful. It’s inspiring. It’s relaxing. It’s amazing.

While we have a very impressive flower database, it’s high time we put together an extensive guide illustrating and explaining the many parts of a flower and plant.

Below is our extensive guide that includes 8 diagrams illustrating the different parts of a flower and plant and their functions. We feature diagrams for the anatomy of a flower, leaf, plant cell as well as illustrations showcasing the process of photosynthesis and more.

Parts of a Flower (Labelled Diagram)

A flower, as you can see, has many different parts; a lot is going on. Here’s a breakdown.

The stigma is the upper part of the pistil. It receives the pollen to affect reproduction.

The style is the long part of the pistil. It provides a place for the pollen tube to grow. It also acts as a barrier for bad pollen.

The pollen tube is a part of the pistil that is located inside of the style. It enables the pollen to go from the stigma through the style to the ovary.

The ovary is the enlarged part of the pistil located at the end of the style.

The ovary is designed to protect the ovules. It’s the job of the ovules to fertilize the pollen to grow it into a seed.

In flowering plants that produce fruit, the ovary usually develops into the fleshy fruit that surrounds the inner seed.

The ovule is located inside of the ovary. Basically, these are the flower’s eggs.

The pollen will travel from the stigma through the style to the ovary. Once in the ovary, the pollen will then fertilize the ovules.

This fertilization ensures the ovule will eventually develop into a seed. In some plants, only a seed will be grown. In other plants, a seed and a fleshy fruit will be grown simultaneously.

The petal is the colored part of the flower that gives it a unique shape.

Petals are often brightly colored to attract insects, birds, bees, and other animals. In this way, the petals aid with the pollination of the plant.

The stamen is considered the “male” part of a flower because it produces the pollen. Its job is reproduction.

The anther is located on the end of the filament. It’s usually fairly compact and is where the pollen is created.

The filament is the long narrow part of the stamen that supports the anther. It connects the anther to the rest of the flower.

The leaf is the part of the flower responsible for making food for the process of photosynthesis. Carbon dioxide, water, and light are turned into glucose.

The stem is the part of the flower that attaches it to the rest of the plant. It also supports the rest of the flower.

In addition to supporting the flower, the stem enables water and nutrients to flow from the soil into the leaf for the process of photosynthesis to take place.

The part of the stem that moves food to the rest of the plant is called the xylem.

The part of the stem that moves water to the rest of the plant is called the phloem.

The cambium is located inside of the stem and provides a continuous cylinder. It enables the food and water to be transported to the rest of the plant together.

Vascular Bundles (Dichotomous Plant)

The vascular bundles of the stem are the groupings of the xylem cells, phloem cells, and cambium. They only occur in dichotomous plants.

The receptacle is where the stem connects to the rest of the flower. It provides support to the rest of the flower.

These are leaf-like structures attached to the outside of the flower. They’re very similar to petals but with the function of enclosing the developing bud. Some sepals are green while others look similar to the flower’s petals.

Plant Structure

Two main systems make up the plant structure. These are the shoot system and the root system.

Shoot System

The shoot system is the above-ground portion of the plant. Its job is to produce leaves, flowers, and more. Here are its individual components:

The tip of the plant’s shoot where new sections of the shoot will grow from.

The outer layer of the plant. Provides protection and creates cuticle. The cuticle layer retains water.

New buds that are ready to grow.

Structures in the leafs to transport water and nutrients throughout the plant.

The central, thick vein in most leaves.

The area between two nodes.

The component of the plant responsible for photosynthesis.

The fleshy ovary that surrounds the seed of certain plants. Encourage animals to eat the fruit to spread the seeds.

The portion of the stem that holds onto leaves.

The long stalk that provides support for the plant. It is also responsible for transporting nutrients from the roots to the rest of the plant.

Root System

The root system is the portion of the plant below ground. Its job is to transport water and nutrients from the soil to the rest of the plant.

The vascular tissue is the component that helps the plant suck up, retain, and circulate water and nutrients.

The roots that extend laterally from the plant to soak up water and nutrients.

The main vertical root that connects to the stem. Lateral roots branch off from this on their search for water and nutrients.

Fine hairs that help the roots soak up even more water and nutrients.

The tip of the bottom of the primary root. It’s where new growth will take place.

The very end of the primary root. It is able to perceive which way is down so the roots can continue looking for water and nutrients.

The cell is the basic unit of life. Plant cells are eukaryotic, meaning they have a cell wall.

These are the parts of a plant cell:

The nucleus stores DNA for the plant and coordinates activity for the rest of the cell (including growth, protein synthesis, and cell division).

The nuclear envelope is the membrane that encloses the rest of the parts of the nucleus inside of it.

The organelle inside the nucleus that works to coordinate all the various essential activities of the cell.

A dense, fiber-like string, the chromatin stores the hereditary material for the plant, also known as DNA.

Holes in the nuclear envelope that allow certain molecules to enter and exit while preventing others from doing so.

Tiny organelle that consist of a mixture of RNA and protein.

Smooth Endoplasmic Reticulum

A series of connected sacs inside of the cytoplasm that transport material through the cell. The “smooth” comes from the lack of ribosomes.

Rough Endoplasmic Reticulum

A series of connected sacs inside of the cytoplasm that transport material through the cell. The “rough” comes from the ribosomes it contains.

The chloroplast is a specialized organelle that gives the plant cell the ability to complete photosynthesis.

These are the small tubes between each plant cell that connect them to each other, enabling the transport of material and information throughout the plant.

Cell Wall

The rigid wall that surrounds the entire plant cell and all of its inner parts to provide protection and regulate its many functions.

Plasma Membrane

Similar to the cell wall, except that it’s a flexible layer of protection just inside the cell wall’s boundaries.

The cytoplasm is a gel-like substance that contains water, organelles, and nutrients. It’s located inside the cell membrane.

An important cellular structure that helps store material, provide growth and reproduction, and improves protection.

These are rods that provide support to give the entire plant cell its shape.

Very small structures inside the cell that help with the process of photorespiration.

An important component of photosynthesis, mitochondrion work to convert glucose and oxygen into energy.

Golgi Apparatus

The purpose of the Golgi apparatus is to create, store, and send materials (most importantly, protein) throughout the plant cell.

​Leaf Anatomy

The process of photosynthesis is successful largely thanks to a plant’s leaves.

The leaf takes in sunlight, receives water and nutrients from the rest of the plant, and brings in carbon dioxide and produces oxygen to create food for the plant.

The cuticle is the waxy surface on the outside of the leaf. Its job is to prevent the leaf from losing valuable water.

Located inside the veins of the leaf, the xylem is a layer of cells that transports water throughout the plant.

Also located inside the veins of the leaf, the phloem is a layer of cells that transports nutrients (mainly sugar) throughout the plant.

The stomata (plural for stoma) are small pores in the epidermis that open and close to release or retain oxygen, carbon dioxide, and water.

Tubes made out of vascular tissues that work with the xylem and phloem to transport water and nutrients throughout the plant.

6. Spongy Mesophyll

The spongy mesophyll are loosely packed cells in the middle of the leaf. The air between the cells allows for the capture and release of gas. They contain a lot of chloroplasts.

7. Palisade Mesophyll

Column-like layers of cells between the epidermis and spongy mesophyll. Also full of chloroplasts.

The outer layer of cells in the leaf. It’s located directly below the cuticle. Contains special guard cells that tell the stomata when to pen and close.

Chloroplast Structure

1. Plant Cell

The chloroplast itself is located inside of each plant cell.

The chloroplast converts sun light into food (sugar) for the plant with the help of water and carbon dioxide.

Special thylakoids stacked on top of each other. They are connected to each other by separate thylakoids.

A special internal membrane system where the process of photosynthesis takes place.

5. Thylakoid Lumen

The internal portion of each thylakoid that contains the molecules necessary for photosynthesis.

1. Thylakoid Space

The area where the thylakoids are located.

The “skeleton” of the chloroplast. They protect all of the cells.

The name for a single thylakoid stack.

4. Stroma Lamellae

The connecting membrane between each granum.

5. Outer Membrane

The outer membrane is the outer layer that protects the inside workings of the chloroplast.

6. Inner Membrane

A softer layer, the inner membrane protects the stroma and grana.

A protein-rich component that affixes carbon to the food molecules and synthesizes sugar.

Photosynthesis Process

Photosynthesis is the process that plants use to create their own food with sunlight, water, and carbon dioxide.

The first step consists of the leaves absorbing sunlight and carbon dioxide while the roots absorb water.

The chlorophyll uses the energy from the sunlight to break water into hydrogen and oxygen. The oxygen is released into the atmosphere while the hydrogen bonds with carbon dioxide to create sugar.

The plants then use this sugar as food/energy.

ATP is a molecule that stores energy during photosynthesis. NADPH is a molecule that transports this energy.

Both ATP and NADPH are involved in the Calvin Cycle. This is when the carbon dioxide and the glucose are combined to make sugar.

Plant Photosynthesis & Respiration Cycle

Photosynthesis and respiration are two processes that are very important to the survival of plants.

In fact, the two processes depend upon one another. You can’t have photosynthesis without respiration and vice versa.

Photosynthesis is the process that plants use to convert sunlight, carbon dioxide, and water into food (glucose). Oxygen is released as a byproduct of this process.

Cellular respiration is, in many ways, the opposite process. It consists of the breakdown of the food (glucose) into energy. It’s how plants burn and metabolize the food. Carbon dioxide and water are byproducts of this process.

Despite their similarities, photosynthesis and cellular respiration are very different. Below we explain the specifics of each process in greater detail. You may also like: Plants and Flowers that Start with “B”

Photosynthesis is the process that plants use to convert sunlight, carbon dioxide, and water into food.

It takes place in the leaves of plants. A component of the leaves known as chlorophyll kickstarts the process of photosynthesis.

But first water must travel from the roots of the plant through the stem to the leaves. Here it waits in the chlorophyll for photosynthesis to begin.

At the same time, the leaves are taking in carbon dioxide from the atmosphere. It meets with the water to be used during photosynthesis.

Sunlight is the final ingredient in the recipe that is photosynthesis. It’s what gives the chlorophyll the energy needed to combine the water and carbon dioxide into glucose.

A series of chemical reactions take place within the leave, mostly in the chlorophyll, to turn sunlight, water, and carbon dioxide into glucose the plant can use as food to survive.

In addition to glucose, the process creates oxygen. The oxygen is then released into the atmosphere for other living organisms to consume.

The two main chemical reactions that take place during photosynthesis are light-dependent reactions and light-independent reactions.

Light-dependent reactions are those that take place in the sunlight. Molecules known as ATP and NADPH are produced thanks to this sun energy.

Light-independent reactions take place once ATP and NADPH are produced. These molecules are used to fuel chemical reactions known as the Calvin Cycle.

The Calvin Cycle is when carbon dioxide molecules are broken down and combined with water to create glucose. It’s also when the oxygen is released as a byproduct.

Photosynthesis can only take place during daytime hours since it requires sunlight to complete.

Simply put, water plus carbon dioxide creates oxygen and glucose to fuel the plant. That’s photosynthesis.
Respiration

Photosynthesis is a process that only takes place in plants (as well as some algae). Animals can’t use photosynthesis.

Cellular respiration, on the other hand, takes place in both plants and animals. In fact, plant respiration is very similar to animal respiration.

Both plants and animals use the process of respiration to convert food into energy.

During respiration, plants take in water from their roots and stems. This is then sent to the leaves to await photosynthesis in the chlorophyll.

Oxygen and glucose are also taken in by the leaves of the plant. As the energy is used and metabolized by the plant, carbon dioxide and water (in the form of dew) is released by the plant.

The plant cell’s mitochondria and cytoplasm are responsible for respiration while the chlorophyll is responsible for photosynthesis.

Plant respiration is similar to the way that animal’s breath. Though not exactly the same, they both accomplish much the same goal. It’s a way for the plant to get rid of byproducts while also pulling in required nutrients.

Cellular respiration takes place both during the night and during the daytime while photosynthesis only takes place during the sunlight hours.

Simply put, oxygen plus glucose creates water and carbon dioxide that’s expelled from the plant. That’s respiration.

Full Flower & Plant Infographic

We welcome you to pin any diagrams on this page, but below is our full infographic ideal for Pinterest.

HomeParts of a Flower and Plant and Their Functions (8 Diagrams: Flower, Cell, Leaf, Stem etc.)

Most plants produce a fibrous root system, a taproot system, or most commonly a combination of both. However, some plants have roots with modifications that allow specific functions in addition to the absorption of water and minerals in solution.

Food-storage roots

In certain plants, the roots, or part of the root system, is enlarged in order to store large quantities of starch and other carbohydrates. Sweet potatoes and yams, for example, have extra cambial cells that develop in the xylem portion of branch roots. The cambial cells produce numerous parenchyma cells that cause the organs to swell. Starches are then stored in the swollen areas of the root. Carrots, beets, and turnips have storage organs that are actually a combination of root and stem. Approximately, the top two centimeters of a carrot are actually derived from the stem. Although, you likely will not be able to see the origin of the cells just by looking at a carrot.

Water-storage roots

Plants that grow in particularly arid regions are known for growing structures used to retain water. Some plants in the Pumpkin Family produce huge water-storing roots. The plant will then use the stored water in times or seasons of low precipitation. Some cultures will harvest the water storing root and use them for drinking water. Plants storing up to 159 pounds (72 kilograms) of water in a single major root have been found and documented.

Propagative roots

To propagate means to produce more of oneself. Propagative root structures are one way for a plant to produce more of itself. Adventitious buds are buds that appear in unusual places. Many plants will produce these buds along the roots that grow near the surface of the ground. Suckers, or aerial stems with rootlets, will develop from these adventitious buds. The ‘new’ plant can be separated from the original plant and can grow independently. Some plants will produce propagative roots up to 30 feet or more away from the parent plant. This can be a nuisance for some people, while others may enjoy the propagative qualities of their cherry tree, strawberries or horseradish plants.

Pneumatophores

Pneumatophores are spongy roots that develop in most plants that grow in water. Swamps, marshes, and coastal areas are good places to find plants with pneumatophores. These specialized roots account for the fact that water, even after having air bubbled through it, has less than one-thirtieth of the amount of free oxygen that is found in the air. Plants growing in water may require additional methods of obtaining oxygen for respiration. Pneumatophores fill that need by rising above the water surface and facilitating gas exchange.

There are many different kinds of aerial roots produced by a wide variety of plants. Orchids produce velamen roots, corn plants have prop roots, ivies have adventitious roots, and vanilla orchids even have photosynthetic roots that can manufacture food. Banyan trees have aerial roots that grow down from the tree branches until they touch find the soil. In a nutshell, aerial roots are roots that are not covered by soil hence out in the air. They can facilitate climbing and various types of support as demonstrated by ivies and creeper plants.

Contractile roots

Contractile roots are roots that pull the plant deeper into the soil. Lily bulbs are a good example, as each bulb is pulled a little further into the soil as additional contractile roots are developed each year. When a region of stable temperature is reached, the contractile roots quit pulling. Dandelions also have contractile roots, and their presence is noticeable because the lower leaves may look like they are coming right out of the ground. In reality, the roots are pulling the stem downward. The actual mechanism of contraction involves the thickening and constriction of parenchyma cells. This causes the components of xylem to spiral into a corkscrew shape. The portion of the root that contracts may lose up to two-thirds of its length within weeks.

Buttress roots

Tropical trees may have large buttress roots at the base of the trunk. These roots add stability to the tree and give an angular look to the lower visible portion of the trunk.

Haustoria

Some plants, such as dodders, broomrapes, and pinedrops do not have chlorophyll. They will parasitize other plants and utilize their chlorophyll and food making abilities. The parasitic mechanism involves rootlike projections called haustoria (singular haustorium). These projections develop along stems that are in contact with the host. They will penetrate the outer tissues of the host plant and will tap into the water and food conducting tissues (xylem and phloem). Other plants with chlorophyll, such as mistletoes, will also form haustoria in order to obtain water and dissolved minerals from host plants. They are capable of producing their own food and thus are considered to be partially parasitic.

Mycorrhizae

Mycorrhizae are fungal roots found in many plants. These fungal associations are important for both the plant and for the fungal and are therefore considered to be mutualistic. Essentially, the fungus will have a greater capacity for absorbing phosphorus than root hairs alone. The fungus will also grow and increase the absorption of water and other nutrients. In return, the plant provides sugars and amino acids vital to the survival of the fungus. Plants with mycorrhizae generally have fewer root hairs than those without. Nearly all woody trees and shrubs found in forests have fungal associations in their root systems. However, it has been demonstrated that mycorrhizae are particularly susceptible to acid rain. This may have a direct impact on forest health and maintenance.

Root nodules

It is important to note that root nodules are not root knots, which are root swellings in response to worm invasions. Root nodules are beneficial bacterial colonies that are visible as small swellings in the root system. The bacteria aid the plant in fixing, or converting, atmospheric nitrogen into a form that the plant can use. Root nodules are found extensively throughout the legume family. A nodule develops when a substance leaked into the soil by plant roots stimulates Rhizobium bacteria to produce another substance that caused root hairs to bend sharply. The bacterium may attach in the crook of the bend and then ‘invade’ the cell with a tubular infection thread. This thread does not penetrate the cell wall and plasma membrane. The thread, does, however, grow through to the cortex which is stimulated to produce new cells that will become part of the housing for the bacterium. As the bacteria multiply and the colony grows, the nodule will swell. It is in the crook of root hairs that the nitrogen-fixing takes place.

Recommended reading: Whipps, J. M. (2001). Microbial interactions and biocontrol in the rhizosphere. Journal of Experimental Botany, 52(suppl 1), 487–511. https://doi.org/10.1093/jexbot/52.suppl_1.487.

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Root Structure

Historically, developing roots have been categorized into four zones of development. These are not strict zones, but rather regions of cells that gradually develop into those of the next region. The zones vary widely as far as extent and levels of development.

Regions of root development:

We will discuss each region in greater detail.

Root cap

In some plants, the root cap is quite large and obvious, while in others it is nearly impossible to find. The root cap is made of parenchyma cells that form a thimble shape, as a covering for the tip of each root. The cap serves several functions. The main function being protection as the delicate root tip pushes through soil particles. In the outer cells of the root cap, the Golgi bodies secrete a slimy substance that lodges in the walls and eventually pass to the outside. As the cells slough off, replaced from the inside, they form a slimy lubricant that aids root tip movement through the soil. In addition, to aiding movement, the slime is a supportive medium for beneficial bacteria.

The root cap serves in additional capacity in determining the root growth direction. As the root cap has a life span of about one week, it can serve for some interesting experiments. Whether the cap sloughs off or is cut off, the root will grow in random directions, as opposed to downward, until a new root cap is formed. This lends support to the notion that the root cap functions in the perception of gravity. On the sides of the root cap amyloplasts, or plastids containing starch grains, collect facing the direction of gravitational force. In documented experiments, when the root is tipped horizontally from its vertical growing position, the amyloplasts will reshift themselves to the “bottom” of the cells in which they are found. In a short time or 30 minutes to a few hours, the root will resume growing downward. While the exact nature of this gravitational response, or gravitropism, is not fully known, there is some evidence that the calcium ions found in amyloplasts do influence the distribution of growth hormones in plant cells.

Region of cell division

The region of cell division is the next zone in the root cap. The root cap arises from the cells in this zone. This inverted cup-shaped region is composed of an apical meristem at its edges. The cells divide every 12 to 36 hours at the tip of the meristem, while the ones at the base of the meristem may divide once every 200 to 500 hours. Interestingly enough, the divisions are rhythmic and peak usually twice a day around noon and midnight. In the interim, the cells are not usually dividing. Most of the cells in this region are cube-shaped with fairly large nuclei and few, if any, small vacuoles. As in stems as well, the apical meristem in the roots will subdivide and give rise to three meristematic areas: the protoderm, which gives rise to the epidermis; just to the inside of the protoderm, the ground meristem, which produces parenchyma cells of the cortex; and the solid-looking cylinder in the center of the root, the procambium, which produces primary xylem and phloem. The central pith tissue is found in many monocots, such as grasses, but is generally not seen in mature dicot plants due to compression by the vascular cylinder.

This region is merged with the upper (toward the soil surface), region of the root apical meristem. It is in this region that the cells become several times their original length, and somewhat wider. The tiny vacuoles in each cell will merge and become one or two large vacuoles. In their final state, the enlarged vacuoles will account for up to 90% or more of the cellular volume. As only the root cap and apical meristem are actually moving through the soil, no further increase in cell size occurs above the region of elongation. While the elongated portions of the root generally remain stationary for the rest of their life, if a cambium is present there may be secondary growth and an increase in root girth.

The region of maturation is sometimes also called the region of differentiation or root-hair zone. In this region, cells mature into the various types of primary tissues. Recall that root hairs are extensions of the epidermis that serve to increase surface area and aid in the absorption of water and soil nutrients. If the region of maturation is examined carefully, it would be noted that the cuticle is very thin on the root hairs and epidermal cells of roots. It is understood that any significant amount of fatty substance would interfere with the ability to absorb water, as fats are hydrophobic—or water-repelling. A root in cross-section would have an epidermis, cortex, endodermis, xylem, phloem, and a pericycle. The cortex is the tissue at the immediate inside of the epidermis that functions in storing food. Generally, the cortex is many cells thick and similar to the cortex of stems, with the exception of the presence of a root endodermis at the inner boundary. In stems, an endodermis is quite rare, while in roots only three species of plants are known to lack a root endodermis. The endodermis is a cylinder formed by a single layer of tightly arranged cells. The primary walls of these cells contain suberin. The waterproof suberin forms bands, called Casparian strips, around the cell walls perpendicular to the root’s surface. The barrier that is formed forces all water and dissolved substances entering and leaving the central tissue core to pass through the plasma membrane or their plasmodesmata. This entire structure serves to regulate the types of minerals absorbed and transported by the root to the stems.

Next to the inside of the endodermis is a cylinder of parenchyma cells called the pericycle. The pericycle is generally one cell wide, however, it can extend for several cells depending on the plant. It is a vital tissue, as the pericycle is the point of origin for the lateral branch roots, and if it is a dicot, part of the vascular cambium. The cells in the pericycle retain their ability to divide even after they have matured. Primary xylem, which contains water-conducting cells, forms at the core of the root and may or may not have observable ‘branches’ which extend like an ‘x’ to the pericycle. The primary phloem, which contains the food conducting cells, fills in the spaces between the branches of xylem. Any branch roots will usually arise in the pericycle opposite the xylem branches.