Anatomy and histochemistry of Utricularia reniformis stolons. (A, B) General stolon anatomy. Note the parenchymatous cortex (Pc), which surrounds the ectophloic central cylinder (CC). pf, phloem; x, xylem. Scale bar = 100 µm. (C) Reaction for lipids (Sudan IV). Arrows indicate small lipid droplets. Scale bar = 50 µm. (D) Section after IKI treatment. Note the lack of starch grains. Scale bar = 100 µm. (E) Section treated with ruthenium red for pectins and mucilage. Note the positive pectin reaction in cell walls. Scale bar = 200 µm. (F) Semithin section. Note the giant vacuoles and the nucleus with paracrystalline protein inclusions. Scale bar = 20 µm.