extrafloral

**Extrafloral Nectaries**

Extrafloral nectaries (EFNs) are specialized structures found on the leaves, stems, or other parts of certain plants, distinct from the floral nectaries that produce nectar for pollinators. These nectaries serve a protective rather than reproductive function, attracting ants and other beneficial insects that deter herbivores and pathogens. The term "extrafloral" indicates that these structures are separate from the plant’s reproductive flowers.

EFNs are commonly observed in plants from various families, including Fabaceae (legumes), Asteraceae, and Rutaceae, among others. They often appear as small, raised glands along the leaf edges, margins, or stems. The nectar produced by these glands is typically rich in sugars and amino acids, providing a food source for ants, which in turn provide mutualistic benefits such as defense against pests.

The relationship between plants and ants, facilitated by EFNs, is known as ant-plant mutualism. Ants may guard the plant by attacking herbivores or fungal pathogens that threaten the EFNs or surrounding tissues. In return, the plant benefits from reduced damage and increased survival rates. This mutualistic interaction has been documented in numerous studies, highlighting the ecological significance of EFNs in plant defense strategies.

While EFNs are primarily associated with herbivore deterrence, they can also play a role in nutrient cycling and seed dispersal in some cases. Their presence underscores the complexity of plant-insect interactions and the adaptive strategies plants employ to ensure their survival and reproduction. Research on EFNs continues to expand our understanding of plant defense mechanisms and the broader ecological dynamics of plant-animal relationships.