Quote:
Originally Posted by PeterJL  AlanS who posts on here is a national expert on Euphrasia and he delivered a talk to BSBI last year with photos. You can download the photos from his site if you have powerpoint: Alan Silverside - research index |
Ah yes, I really intended that the PowerPoint would be up for a limited time, but it is still there at present. There are various signs in it that final production was hurried - typographical errors, statements not as clear as they might have been - but of course it was to illustrate the talk I was giving and was never designed to stand alone. I had thought of reformatting much of it into an online guide to
Euphrasia and may still do so, but that would take more time than I have available at present.
A warning to anyone who downloads it that it is also a very large file (24 mB). I was ensuring that the photographs would have good definition in my talk (well, as good as the photographs themselves allowed!) and I used very little compression. Anyone downloading it had better have broadband!
Anyhow, IanS, what do you mean by "Chalk Eyebright". Some have attempted to make up common names for these, but they are not generally used and not adopted by the BSBI.
One of the two main species on chalk is
Euphrasia pseudokerneri - but this is very local, confined to the really "good" bits of herb-rich chalk turf and it will not be in flower for another month.
The other is
E. nemorosa, which is common on the chalk, but also locally frequent in herb-rich grassland generally (in England at least, less so in Wales and Scotland). It is in flower right now.
There are photographs of both, with some identification pointers, in my PowerPoint, but both species are variable.
If you post Eyebright pictures I'll give my opinion when I can (bearing in mind I shall often be away). But identification from a photograph will not always be possible. When I name Eyebrights for BSBI members, I need to see enough material to show the range of variation. I then almost invariably use a stereo microscope to examine the several critically important features.
Also bear in mind that they all hybridise to a lesser or greater extent. Most hybrids are fertile and sometimes hybrids completely replace the parents or spread independently. For the forthcoming BSBI book on hybrids I have accepted 66 different hybrids! (And I have been asked to check the validity of a few more.)
And since we are carrying out ongoing DNA studies, we may yet move the goalposts ....
Alan Silverside