The image shows protonemal tissue of moss Physcomitrium patens. The tissue is composed of longer caulonemal cells with less chloroplast that grow away from the main plant (top part of the image) and shorted chloronemal cells filled with large chloroplasts (at the bottom of the image). The caulonemal cells explore new areas and expand the plant, while chloronemal cells are the main site of photosynthesis. Plant cell walls (here presented in blue) were stained with calcofluor white, which fluorescently labels cellulose and other wall components. In the cell interior, chloroplasts are visible (in yellow), due to the natural autofluorescence of chlorophyll. All other cellular organelles were not fluorescently labeled so they appear as black space. The image is a maximum projection of the deconvolved Z-stack.
