Structure and biology of extrafloral nectary in Desmanthus varigatus

The structure of the extrafloral nectaries in Desmanthus varigatus was studied at the level of light microscope. A shallow cup shaped, non‐porate nectary present at the rachis base and had developed from a group of initials of hypodermal origin. The mature nectaries were supplied by phloem and had non‐glandular, cuticularized trichomes at their epidermal surfaces. Secreting nectaries appeared susceptable to fungal growth. Only non‐agressive ants visit the nectaries and the secretion was observed during morning hours. It is suggested that ants may have a little role in plant defence.