Field of Science

Sphagnum centrale

This is a cross section through a Sphagnum leaf. The leaf is unistratose, one cell layer thick and the pattern of chlorophyllose cells interspersed between hyaline cells can be seen. In this leaf the chlorophyllose cells are oval in shape and located directly in the middle of the line of cells. Examining the leaf cells in this manner is used to distinguish species of Sphagnum. The chlorophyllose cells may be a particular shape and they may be located toward the upper or lower surface of the leaf. Unfortunately this is a characteristic that requires making a very thin section through a leaf and a compound microscope. As I mentioned earlier determining the species of Sphagnum that you locate can be challenging, but not impossible.

3 comments:

  1. Hi- I don't suppose you have any advice on the best way to section a Sphagnum leaf? I have some fine sectioning blades, but I'm having trouble making a thin enough section that can be turned on its side. Any help appreciated!

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  2. Hey Daniel,
    For sectioning moss leaves I use a dissecting scope, a pin tool (a needle on a wooden handle) and thin razor blades. The blades that I use are the double sided mens shaving blades. I crack them in half and then use one side. Alternatively you can use the heavier one-sided straight-edge razor blades. I use the pin tool to hold the leaf in place in a drop of water and then section with the blade. I stabilize one corner of the blade on the microscope slide I am cutting and then bring the other corner of the blade down like an old-school paper cutter. The blades can dull pretty fast and I often switch to a new one if the cuts are no longer clean.
    It can be quite a trial getting good transverse sections of leaves and it usually takes me a while to get a good one, especially if I want to photograph it.

    Best of Luck!

    Jessica

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  3. Thanks a lot for the advice Jessica- I will give this a try!

    Most of the specimens I examine are fossil specimens from peat bogs (University of Reading PhD!), but I'm hoping that they won't prove impossible to section.

    Thanks again,

    Dan

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