Lenticels

Definition

Lenticels are small, raised pores found on the stems and some other parts of woody plants that facilitate gas exchange between the internal tissues and the atmosphere. These structures allow for the diffusion of oxygen and carbon dioxide, which is crucial for respiration in the plant, especially in areas where the bark may be too thick to allow gas exchange through traditional stomata.

5 Must Know Facts For Your Next Test

1. Lenticels are typically more abundant in younger stems and can be found in various shapes and sizes, depending on the plant species.
2. They are formed from parenchyma cells that are loosely arranged to create air spaces, allowing for efficient gas diffusion.
3. Lenticels can vary in number and size based on environmental conditions, such as humidity and temperature, influencing a plant's respiratory efficiency.
4. These structures are essential for woody plants as they age because the thickening of bark can limit the functionality of stomata, making lenticels a vital adaptation.
5. Lenticels are usually visible as small bumps or dots on the surface of stems and branches, often contrasting with the surrounding bark color.

Review Questions

• How do lenticels function differently than stomata in facilitating gas exchange in woody plants?
  • Lenticels function differently than stomata primarily due to their location and structure. While stomata are found on leaf surfaces and regulate gas exchange through opening and closing mechanisms, lenticels are permanently open pores located on stems that allow continuous gas exchange. This is especially important for woody plants where thick bark can obstruct normal respiration, making lenticels essential for oxygen intake and carbon dioxide release in these areas.
• Discuss the adaptations that lenticels provide to woody plants compared to non-woody plants.
  • Lenticels provide significant adaptations for woody plants by allowing gas exchange through thickened bark where stomata cannot function effectively. As woody plants grow, their bark becomes thicker, which would otherwise limit gas exchange necessary for respiration. Lenticels help maintain vital respiratory processes in these plants by creating openings that promote airflow without compromising structural integrity, thus playing a critical role in their overall health and growth.
• Evaluate the importance of lenticels in relation to environmental factors affecting plant respiration in woody species.
  • Lenticels play a crucial role in plant respiration, particularly under varying environmental conditions. For instance, in humid climates, lenticels may expand to enhance gas exchange, while in drier conditions they can help prevent water loss while still allowing necessary gas movement. This adaptability ensures that woody species can maintain effective respiration even as their bark thickens with age or when external conditions change significantly. Evaluating this importance shows how lenticels are integral to a plant's survival strategy in diverse habitats.

Related terms

Stomata: Small openings on the surfaces of leaves and stems that regulate gas exchange and transpiration in plants.

Bark: The outer protective layer of a tree or woody plant, which can sometimes inhibit gas exchange and necessitates the presence of lenticels.

Photosynthesis: The process by which green plants use sunlight to synthesize foods with the help of chlorophyll, requiring both carbon dioxide and oxygen.