Lenticels: Understanding Plant Gas Exchange - Definition & Function

Lenticels are small, corky pores on the stems and roots of woody plants that facilitate gas exchange between the plant and the atmosphere. They are present in all woody plants but are especially noticeable on tree and shrub stems.

Formation

Lenticels form when the outer cell layer ruptures, exposing inner cells that produce a corky substance (suberin) to seal the pore, preventing excessive water loss.

Function

• Respiration: Oxygen diffuses in; carbon dioxide diffuses out.
• Transport: Gas exchange supports water and nutrient movement from roots to leaves.
• Defense: The corky seal blocks entry of pathogens (bacteria, fungi).

Variation

Size, shape, and arrangement vary by species—some are barely visible, others prominent; they may be evenly spaced or clustered.

Lenticels are vital for woody plant respiration and pathogen defense.