What is the Difference Between Stomata and Lenticels

The main difference between stomata and lenticels is that stomata mainly occur in the lower epidermis of leaves, whereas lenticels occur in the periderm of the woody trunk or stems. Furthermore, the size of the stomata is determined based on the requirements of the plant while lenticels remain opened. 

Stomata and lenticels are two types of small pores, which occur in plants. Generally, they are responsible for the gas exchange. Stomata occur during the primary growth of the plant while lenticels occur during the secondary growth of the plant. 

Key Areas Covered 

1. What are Stomata
     – Definition, Structure, Function
2. What are Lenticels
     – Definition, Structure, Function
3. What are the Similarities Between Stomata and Lenticels
     – Outline of Common Features
4. What is the Difference Between Stomata and Lenticels
     – Comparison of Key Differences

Key Terms 

Epidermis, Gas Exchange, Lenticels, Peridermis, Pores, Stomata

What are Stomata 

Stomata are the small pores responsible for the gas exchange in terrestrial plants. Generally, they facilitate the intake of carbon dioxide into the leaf while removing oxygen and water vapour to the outside. Basically, guard cells surround stomata. They are parenchyma cells, containing chloroplasts as well. The main function of guard cells is to control the size of the stomata. However, this is by changing the turgidity of guard cells. 

Figure 2: Stomata

Furthermore, when water is readily available, guard cells become turgid, opening the stomata. However, when water is not available, guard cells become flaccid. Moreover, water potential determines the turgidity of guard cells. Meanwhile, when the solute concentration inside guard cells is increased by the gradual movement of potassium and chloride ions, water potential increases with the movement of water into the guard cells. Then, this increases the turgor pressure of the guard cells. In contrast, under water stress in hot and dry conditions, guard cells efflux water by removing excess ions. Therefore, this reduces the turgor pressure, closing stomata. Moreover, although stomata remain opened during the day time, they tend to close at night. 

What are Lenticels 

Lenticels are the small pores, occurring in the stem and root during the secondary growth of plants. Their main function is to exchange gases between inside tissues and the outside environment. Generally, lenticels are porous tissue, having cells with large intercellular spaces in the periderm of the dicotyledonous flowering plants. On the other hand, they appear as raised circular, elongated or oval areas on both stems and root.

Figure 2: Lenticel

Moreover, lenticels also occur in fruits. They are quite noticeable in apples and pears. Lenticels remain open during the day and night. However, they become the prominent method of gas exchange during the night with the closing of stomata. 

Similarities Between Stomata and Lenticels 

• Stomata and lenticels are two types of small pores that occur in plants. 
• They are mainly responsible for gas exchange. 
• Moreover, they facilitate the release of water vapour from the plant to the outside. 

Difference Between Stomata and Lenticels 

Definition 

Stomata refer to minute pores in the epidermis of the leaf or stem of the plant, forming slits of variable width, which allows the movement of gases in and out of the intercellular spaces while lenticels refer to the many raised pores in the stem of a woody plant, allowing gas exchange between the atmosphere and the internal tissues.

Occurrence 

Furthermore, stomata mainly occur in the lower epidermis of the leaf while lenticels occur in the periderm of the woody trunk or the stem. Thus, this is the main difference between stomata and lenticels.

Type of Growth 

While stomata occur during the primary growth, lenticels occur during the secondary growth of the plant. 

Opening 

Stomata open based on the requirements of the plant while lenticels remain opened. 

Guard Cells 

Another difference between stomata and lenticels is the presence of guard cells. Guard cells determine the size of the stomata, while lenticels do not contain guard cells. 

Transpiration 

Moreover, stomata transpire a large amount of water vapor while lenticels transpire a small amount of water vapor. 

Conclusion 

Stomata are the small pores that occur at the lower epidermis of the leaf. Two guard cells surround a stoma, determining its size. Generally, stomata open during the day time. On the other hand, lenticels are small pores on the peridermis of the woody stem. Therefore, they occur during the secondary growth of the plant. Moreover, they do not transpire a lot of water vapor. However, the main difference between stomata and lenticels is their occurrence in the plant. 

References:

1. Hares, Khadija. “Stomata and Lenticels BIOLOGY.” Prezi.com, 26 June 2013, Available Here.

Image Courtesy:

1. “Zebrina stomata” By AioftheStorm – Own work (CC0) via Commons Wikimedia   
2. “Woody Dicot Stem: Lenticel Development in Sambucus” By Berkshire Community College Bioscience Image Library (Pubic Domain) via Flickr