Term:

Nectar chamber
Definition:

A chamber at the apex of the coils of zygomorphic-flowered species or at the base of the staminal tube of most Old World species and in some actinomorphic-flowered genera in the New World, e.g., for example of species of . The nectar that accumulates in the nectar chambers serves as the reward that attracts pollinators to the flowers.
Notes:

Nectar chambers are found only in species of Eschweilera sensu lato and species of Couratari. Zygomorphic-flowered species of Lecythidaceae with only a single inward coil do not have apparent nectaries--they may, however, produce nectar at the base of the vestigial stamens on the inner side of the single coil. Nectar chambers that accumulate nectar produced by nectary discs are thought to occur in Grias and species of Allantoma and Cariniana.