The diversity of cell sizes in the Arabidopsis sepal epidermis. (a) A scanning electron micrograph (SEM) of the sepal epidermis shows large giant cells are interspersed between smaller cells in a range of sizes. (b) A confocal maximum intensity projection of the sepal epidermis in which the cells are outlined in red by the plasma membrane dye FM4-64 revealing the variation in cell sizes. The nuclear size shown in green (ML1::H2B-mYFP) corresponds with the ploidy. The correlation between cell size and ploidy is evident: large cells have large nuclei indicating that they have undergone endoreduplciation whereas small cells have small nuclei indicating that they have remained diploid. Scale bars represent 50 μm.