Abstract: Each glandular hair of Nyrnphoides peltaturn (Gmel.) O. Kuntz consisted of only one row of cylindar cells with secretory function. The hairs originated from the protoderm cells on the adaxial surface of the second leaf primordium from the shoot apex. Cells of the glandular hairs prossessed dense cytoplast during the secretory period, but the vacuoles were very small. There were not only abundant mitochondria, Golgi bodies and endoplasmic reticulum in the glandular hair cells, but also many plasmodesmata. The authors' research indicated that the mucilage was carried to the edge of the cells by the membranous multilamellar bodies and the vesicles from both Golgi bodies and endoplasmic reticulum. The mucilage was secreted extracellularly by either exocytosis or ecrine secretion. The side walls of the glandular hairs swelled because of mucilage mass accumulation in the walls. The mucilage, being tested to be composed of polysaccharides and a trace of protein, played an important role in protecting the development of the vegetative buds of N. peltatum.

Key words: Nyrnphoides peltaturn, Glandular hair, Development, Secretion, Ultrastructure