Moss Hand Sections
Posted: Tue Dec 18, 2018 8:38 pm
Hi all, I've been practising with moss leaf and stem today, trying out the taking of hand sections cut along the edge of a slide placed over the leaf or stem to be cut.
Thought I'd share a few images, hope to do a few more tomorrow if I get the chance. These are all temporarily mounted in neat PVA glue and coverslip, imaged with my Orthoplan compound 'scope.
Here are top and bottom views of a leaf, almost identical except for the central 'nerve'...
The leaf has a long, finely-toothed 'hair' that's nearly as long as the leaf-blade!
Underside where hair leaves leaf-tip,
There's a mid-rib or 'nerve' as these thickened central strands are called in mosses. The above hair-tip is an extension of this nerve it seems.
The edges of the leaf are 'rolled under' from the base to about halfway up the blade,
Halfway up the edge 'flattens out',
The edge of the leaf looks pretty papillose, as do the blade (lamina) cells, at least in the upper regions of the leaf,
Towards the leaf base the cells become elongated and 'hyaline' (having some translucency),
and,
This moss also has rhizoids at the base of it's leaves, seen here around the base of a detached leaf as the brownish filaments,
In transverse-section the leaf is seen to have a central nerve with a degree of cellular differentiation, namely thickened cells 'around' the bottom of the nerve with top/central larger-bore water-conducting (maybe?) cells within this strengthened 'jacket or cylinder. The top edge of the nerve is pretty flat and level with the leaf blade, and looks papillose as do the leaf edge and blade....
The stem in TS doesn't appear to have a well defined central 'core' as seen in the leaf nerve, but these are just unstained hand sections, maybe closer inspection and staining would reveal a more definitive image..... There appear to be rhizoids or maybe 'paraphyllia' emerging along the surface of the stem also. The thickened epidermis and maybe even a cortex of sorts are evident, also chlorophyll seems to extend quite a way into the cortex, beyond the epidermis.
Closer-in the transition from thinner to thicker cell walls is seen from center to cortex to epidermis across the stem,
The cells at the center seem thin-walled and not really larger or noticeably adapted for water transport as in some mosses,
Finally a couple of gratuitous polarised images across the stem,
and,
Well, sorry to bombard with images, I just thought some of them were interesting and that I may as well share them. It's amazing to see just what may be discovered from a tiny piece of moss stem and a few attached leaves. Next time I must take the time to do a 'proper job' and include capsules if I can find some - it's a little early for mature capsules here in the U.K. A touch of staining would be nice too I think!
In fact, it's about time I made some permanent sections of moss features, hmm, I really would like to get some made.
Anyway, just a quick indulgence in my 'mossy playtime' of today....
John B.
Thought I'd share a few images, hope to do a few more tomorrow if I get the chance. These are all temporarily mounted in neat PVA glue and coverslip, imaged with my Orthoplan compound 'scope.
Here are top and bottom views of a leaf, almost identical except for the central 'nerve'...
The leaf has a long, finely-toothed 'hair' that's nearly as long as the leaf-blade!
Underside where hair leaves leaf-tip,
There's a mid-rib or 'nerve' as these thickened central strands are called in mosses. The above hair-tip is an extension of this nerve it seems.
The edges of the leaf are 'rolled under' from the base to about halfway up the blade,
Halfway up the edge 'flattens out',
The edge of the leaf looks pretty papillose, as do the blade (lamina) cells, at least in the upper regions of the leaf,
Towards the leaf base the cells become elongated and 'hyaline' (having some translucency),
and,
This moss also has rhizoids at the base of it's leaves, seen here around the base of a detached leaf as the brownish filaments,
In transverse-section the leaf is seen to have a central nerve with a degree of cellular differentiation, namely thickened cells 'around' the bottom of the nerve with top/central larger-bore water-conducting (maybe?) cells within this strengthened 'jacket or cylinder. The top edge of the nerve is pretty flat and level with the leaf blade, and looks papillose as do the leaf edge and blade....
The stem in TS doesn't appear to have a well defined central 'core' as seen in the leaf nerve, but these are just unstained hand sections, maybe closer inspection and staining would reveal a more definitive image..... There appear to be rhizoids or maybe 'paraphyllia' emerging along the surface of the stem also. The thickened epidermis and maybe even a cortex of sorts are evident, also chlorophyll seems to extend quite a way into the cortex, beyond the epidermis.
Closer-in the transition from thinner to thicker cell walls is seen from center to cortex to epidermis across the stem,
The cells at the center seem thin-walled and not really larger or noticeably adapted for water transport as in some mosses,
Finally a couple of gratuitous polarised images across the stem,
and,
Well, sorry to bombard with images, I just thought some of them were interesting and that I may as well share them. It's amazing to see just what may be discovered from a tiny piece of moss stem and a few attached leaves. Next time I must take the time to do a 'proper job' and include capsules if I can find some - it's a little early for mature capsules here in the U.K. A touch of staining would be nice too I think!
In fact, it's about time I made some permanent sections of moss features, hmm, I really would like to get some made.
Anyway, just a quick indulgence in my 'mossy playtime' of today....
John B.