Floral morphology and anther development in diandrous orchid Paphiopedilum purpuratum with their taxonomic implications

The taxonomy of Paphiopedilum Pfitz. has been disputed and needs more data for clarification. Floral morphology and anther development in P. purpuratum were observed using microscope and paraffin section. The results were as follows: (1) It was supported that P. purpuratum should be placed in Paphiopedilum subgenus Paphiopedilum sect. Barbata by some floral features, including a single flower, sepal white with veins, petal spotted with blackish-maroon, pouch of a lip auriculate on both sides, and a staminode lunate. (2) At the early stage, anther primordium developed into a pair of laterally juxtaposed thecae. An incomplete sterile septa was differentiated in the center of each theca, giving rise to two arc-shaped microsporangia. When anther split, the sterile septum was discomposed and degenerated resulting in a mass of sticky pollens from two pollen sacs were fused into a unit. (3) The developed anther wall consisted of an epidermis, an endothecium, a middle layer, and a tapetum, conforming to the monocotyl