Pix of pollen

We are getting a small amount of welcome rain this morning (which is forecast to continue for the next several hours).  When I looked out at our drive I noticed that where the water was puddling against some fallen leaves there was yellow scum around.

This immediately took me back to Spring orienteering in pine forests when one's car would be covered with pine pollen.  We don't have any pine trees upwind of where this was occurring but there are a good number of flowering Acacia dealbata.  Given the apparently unwarranted reputation of Acacias for causing much of the Hay Fever  I was inclined to attribute the scum to them but there is a lot of evidence around that Wattle pollen is not spread by wind.  We do have a lot of grass upwind, but I'm not aware of it flowering at present, so in short I am blowed if I know what the scum is.

Frances has a digital microscope so I sucked up a specimen of gooze and dropped it on a slide.  After a small amount of fiddling to get the correct part of the slide in focus the first image (at 60X magnification) gave this rather brain-like effect.

 I have cropped a part of this ass out to show a little more detail

I then goosed the magnification up to X200 and the first image showed that I had also sucked up some mini-rocks (also visible as the dark lumps in the 60X image).

At this magnification the field of view is rather thin so it was difficult to get things in focus (and even more so to keep them in focus while capturing the image).  However eventually I managed to get a few grains floating with the mini-rocks.

In saying that, I am assuming that the vaguely oval shaped objects with dark ends (like insect eyes) are the pollen grains.

I have found some images of pollen grains on the net which appear to me to simply show that they are very variable in form.

Another image of a pollen grain is here - but I have mainly included that because of the nifty case study and another here (included 'cos its pretty.)!