Foliar, nonstructural nectaries in the Marantaceae

Abstract

Nonstructural, foliar nectaries have been found in two genera of the Marantaceae (Zingiberales). Two nectaries are located on each leaf, at the junction of the leaf sheath and petiole. Externally, they may be readily distinguished from the surrounding tissue by their lighter color and absence of hairs. Internally, they show no specifically differentiated nectariferous tissue. In most species, the location of the nectaries is correlated with the distribution of fiber bundles. In nonncctariferous regions these bundles lie directly beneath the epidermis, while in the region of the nectary they occur several cell layers beneath the epidermis. Nectar secretion takes place through stomates. The cells surrounding the substomatal cavity may play an important role in the process of secretion. The distribution of structural nectaries in the family is also discussed.