Morphology, developmental ultrastructure and ultracytochemistry of staminal hairs in Bulbine inflata (Asphodelaceae) in relation to function

Results of light and electron microscopy and preliminary ultracytochemical studies of the staminal hairs of Bulbine inflata at different stages of development are reported here. The staminal filaments are covered with yellow, unicellular, linear, erecto-patent hairs. These staminal hairs arise directly as single cell outgrowths from epidermal cells of the filament. The surface of each hair is patterned with helical wall thickenings in an anticlockwise direction. This wall is covered by a thick folded cuticle, and formed of a loosely fibrillar cellulose layer. The hair cell possesses a cytoplasm rich in organelles. Especially ribosomes are abundant. Plastids contain large starch grains and peripheral lipid droplets. The smooth endoplasmic reticulum cisternae (SER) encircle the plastids and mitochondria; it is extended in the cytoplasm along the hair length. These hairs have functions in flower pollination attracting pollinators visually, secreting specific substances, providing increased surface area, protecting the filaments and being involved in their movement and vibration.