Fig. 3. Semi‐thin and TEM sections of labellum of M. cf. notylioglossa. A, Semi‐thin transverse section of labellum showing median obpyriform papillae and heavy secretion of viscid material. Note also the short conical papillae at the adaxial margin (top left) and similar papillae on the abaxial surface. Bar = 0·5 mm. B, TEM section of obpyriform papillae. Note the highly vacuolated cells with peripheral cytoplasm and nucleus (bottom right), also the heterogeneous nature of the viscid secretion which accumulates both on the outer tangential wall and intercellularly. Bar = 10 µm. C, Detail of cell showing dense cytoplasm with nucleus (right) and intercellular accumulation of viscid material. Note also that the cytoplasm appears to have withdrawn from the cell wall. Bar = 1 µm.