A couple of pictures of the plant,
and
This plant, as may for some be seen from the parallel leaf-veins, is a monocotyledon, a good subject also for some tissue protocol testing not to mention sectioning, staining and slide-making.
Here are those parallel leaf veins,
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Anyway, here's an image of a stem TS, looing closely at this image this is probably a 5µ section rather than an 8µ, as the central pith-parenchyma cell-walls are quite damaged, whereas the 8µ sections I've cut have perfect paraenchyma.
Closer-in the red/pink stained fibers are clearly visible and may be seen surrounding those vascular bundles that are peripheral.
Here are a few images of individual vascular bundles.
This VB is one of the randomly (seemingly at least....) scattered number typically within the central parenchyma (pith) of the stem. This VB has a line of fibers at each end, but is not surrounded by fibers as are those within that continuous peripheral band of fibers (see next VB image for that type).
Here's said VB within fibers,
Here's one stained with Toluidine-blue stain - a very useful stain to use for a 'quick look' at a new batch of slides, as it shows just about every tissue-type in various shades of blue, purple and sometimes red. I seldom use it though for permanent slide staining as it quite often fades with time, a shame as it can be a beautiful 'metachromatic' stain for many plant tissue types.
Here's a leaf section, shown here through the central main vein in transverse or 'cross' section....
This leaf is interesting as it has a typical leaf structure for a monocot - in that the upper & lower epidermis is of similar cells, and within the leaf the cells are not differentiated into the tall-thin 'palisade' cells and 'spongy mesophyll' cells of a typical dicot leaf, but are all of one type - spongy-mesophyll - spongy in the sense that it is a tissue with a very large percentage of free air-space within, as may be seen from the next image. As a bit of a bonus, the parallel nature of the vascular bundles very often give a much clearer view across the vascular bundles that seen with the angled veins of a dicotyledon...
Closer-in the 'sponginess' of the air-space filled tissue is seen,
A better view, stained with Toluidine-blue and focused on the cell-walls rather than chloroplasts within, to show the multiple branching - often quite 'tubular' nature of the inter-cellular joins, typical of spongy mesophyll. Some spongy mesophyll cells are even X-shaped or U-shaped!
I also sectioned and mounted some of my favourite, but a swine to make well, sections - the 'paradermal' sections of the leaf of this interesting plant. The paradermal section is cut parallel to the surface of the tissue, in this case a leaf. I love these sections as they reveal, to my mind at least, the true nature of the leaf's structure, especially of course when accompanied by the transverse sections as seen above.
A leaf tissue-block orientated for paradermal sectioning will yield relatively few good sections before it is exhausted - which is why I make at least 4 or 5 when I do these....
The sections are always in parts rather than an entire leaf-width as the orientation is very difficult indeed. However, they show the vascular-bundle routes nicely, and as the microtome's blade sections the mesophyll parallel to the surface of the leaf, the complexity of the spongy-mesophyll connections become apparent.
Here's a paradermal section that cuts through several layers of cell-types, from the epidermis and leaf-veins through to the spongy mesophyll below. The epidermal sections also have passed through stomata, enabling their arrangement within the pattern of cells on the surface to be seen, this arrangement varies greatly and is of taxonomic value, often seen in leaf epidermal-peels.
Also visible are the bundles of raphides lying parallel to the surface - the darker-'greyish' cell-sized obejects scattered about in the section, between the veins....
Closer in the details emerge In the image below the section is through the large vein on the left running from image top to bottom, the spongy mesophyll with it's green-stained chroroplasts, air spaces and branched cell shapes and joins, and the outlines (cell-walls) of several stomata stained red by the Safranin....
From the paradermal aspect, the cell shapes are clear,
Veins also,
and
and
Also a surprise when I made these were the rather good views of bundles of crystals (probably raphides of Calcium oxalate) that lie within cells, oriented parallel to the leaf surface, seen also a cross-section with the transverse leaf sections. I'll also add some polarised images of these bundles if I get the time...
Just time for a few raphide pics, flower sections still to come tomorrow.
Here are some with part-polarisation, paradermal view
and crossed polarisers to extinction, paradermal view,
A part-polarised leaf, transverse section view
and
Paradermal bundle of raphides,
Back soon, my battery's about to give-up.
p.s. apologies for the total lack of labels, I'll try to get the time to add some over the weekend....
