Fig. 5

Photomicrographs of thin sections of Vanda Mimi Palmer petal and sepal. a and b are toluidine blue stained resin sections of a petal and sepal. c and d are resin sections stained with periodic acid-Schiff (PAS) and naphthol blue black. a Cross section of a sepal. The adaxial cells are frequently irregularly arranged compared to the regular arrangement of the abaxial cells. b Cross section of a petal. Like the sepal, the epidermal and sub-epidermal cells have big nuclei and dense cytoplasms (polysaccharides). Cross sections of petal (c) and sepal (d). The epidermal and sub-epidermal cells exhibit accumulation of polysaccharides and proteins. The parenchyma cells are mostly empty and loosely packed with large intercellular spaces. Ab Abaxial; Ad Adaxial; Vb Vascular bundles. Arrows indicate the trichomes (some intact, some broken)