Fig. 1: Cellular features of conical cells, short trichomes, and long hairs on Nigella damascena petals.

a The distribution of different cell types on a mature petal under stereomicroscope and scanning electron microscope. Numbered regions (1–4) are magnified to show the micromorphology of long hairs (LHs), short trichomes (STs), conical cells (CCs), and pavement cells (PCs), respectively. b–e Semi-thin sections of regions containing LHs, STs, CCs, and PCs. f–i Propidium iodide (PI) staining of the four cell types. The white arrowhead points to the nucleus. Scale bars: (a left) 100 μm; (a right and b–i) 50 μm. j Total numbers of STs and LHs on each petal. k Lengths of STs and LHs. l The largest PI fluorescence areas of nuclei in the four cell types. m Volumes of reconstructed three-dimensional nuclei in the four cell types. In (j–m), violin outline width shows the density of the data; the thick bar represents the interquartile range (IQR) between the first and third quartiles, with the median marked by a white dot and labeled with the corresponding value; whiskers extend up to 1.5 times the IQR. ^**P < 0.01, ^***P < 0.001 (two-sided Mann-Whitney U test). Source data for (j–m) are provided in Supplementary Data 1. See also Supplementary Fig. 2.