What is the Difference Between Heliophytes and Sciophytes

The key difference between heliophytes and sciophytes is that heliophytes require a high intensity of light to grow while sciophytes need a low intensity of light to grow. 

Light is a vital factor directly affecting the growth and development of plants and for survival. Light is involved in different mechanisms based on plants’ physiological and biological processes, such as the production of chlorophyll, transpiration rate, stomatal movement, and plant distribution. Heliophytes and sciophytes are two types of plants that differ based on their light compensation points.

CONTENTS

1. Overview and Key Difference
2. What are Heliophytes
3. What are Sciophytes
4. Similarities – Heliophytes and Sciophytes
5. Heliophytes vs Sciophytes in Tabular Form
6. Summary – Heliophytes vs Sciophytes

What are Heliophytes?

Heliophytes are sunstroke plants, and they adapt to habitats with very intense solar radiation due to their own structure and metabolism. These plants are common in rocks, meadows, mountain pastures, open terrain, and grasslands, which are exposed to the sun. A few examples of such plants are mint, thyme, white clover, roses, ling, mullein, and soft velcro.

A special feature of heliophytes is the presence of coarse tiny leaves with waxy and hairy protection. This coating acts against excessive light radiation and water loss. The structure of the leaves usually varies with a double palisade layer. Chloroplasts of heliophytes contain protective elements such as carotenoids, enzymes, and reactive oxygen species to avoid any toxic effects. A stoma and green shoots are also present on leaves to facilitate efficient gas exchange. These also help to increase the possibilities of photosynthesis. Heliophytes also have a high light compensation point. This feature requires a higher illumination intensity for an effective adaption of carbon dioxide. In addition, the leaves of heliophytes have a higher basal metabolism when compared to other leaves.

What are Sciophytes?

Sciophytes are a type of plant that requires a lower light compensation point. Therefore, they are known as shade-loving trees or shade plants. They have large photosynthetic units. They reach their saturation level when exposed to 20 % of sunlight. Sciophytes have the ability to adapt to reduced light intensity or partial sun. A few examples of sciophytes include black pepper, cacao, coffee, and ginger.

Sciophytes often grow in the shade and have thinner foliage with a greater surface area. The leaves contain more chlorophyll than plants that receive full sunlight because of the efficient plant foliage. This allows the plants to harvest sunlight at low light levels. Sciophytes comprise many characteristics to use the available energy and for energy conservation. Such characteristics include large thin leaves with a greater chlorophyll content per unit leaf volume, epidermal cells that possess a lens shape to focus the incoming sunlight into the mesophyll cells, narrow stems with longer internodes, thin cuticles, and the presence of stomata on both surfaces, well-developed spongy parenchyma, and trees with fewer branches.

What are the Similarities Between Heliophytes and Sciophytes?

• Heliophytes and sciophytes are two types of plants categorized based on the requirement of light.
• Both heliophytes and sciophytes have a developed stomatal arrangement.

What is the Difference Between Heliophytes and Sciophytes?

Heliophytes require a high intensity of light for growth, while sciophytes require low intensity of light for growth. Thus, this is the key difference between heliophytes and sciophytes. Heliophytes have less developed spongy parenchyma and more developed palisade parenchyma. Sciophytes have more developed spongy parenchyma and less developed palisade parenchyma. Moreover, heliophytes consist of abundant flowering and fruiting, while sciophytes consist of less flowering and fruiting.

The below infographic presents the differences between heliophytes and sciophytes in tabular form for side-by-side comparison.

Summary – Heliophytes vs Sciophytes

Light is a vital factor in the growth, development, and survival of plants. Heliophytes and sciophytes are two types of plants based on their light requirement for growth. Heliophytes require a high intensity of light to grow, while sciophytes require a low intensity of light to grow. Moreover, heliophytes have less developed spongy parenchyma and more developed palisade parenchyma. In contrast, sciophytes have more developed spongy parenchyma and less developed palisade parenchyma. Moreover, heliophytes undergo abundant flowering and fruiting, while sciophytes undergo less flowering and fruiting. So, this summarizes the difference between heliophytes and sciophytes.

Reference:

1. “Define Heliophytes and Sciophytes. Name a Plant from Your Locality That Is Either Heliophyte or Sciophyte.” Vedantu. Class 11 Biology CBSE, 28 July 2021.

Image Courtesy:

1. “Heliofite” By Gmihail at Serbian Wikipedia – Own work (CC BY-SA 3.0 rs) via Commons Wikimedia
2. “Sciophytes” By Gmihail at Serbian Wikipedia – Own work (CC BY-SA 3.0 rs) via Commons Wikimedia