Hi John
Thanks for this. Unfortunately, unless these are conidial spores(?) they do not match P. obscura or P. luzulae (the two species in E&E on wood rush). Nor do they match P. poarum. Info on P. obtusa is proving elusive (two further species which have been recorded by the BMS on wr). Of these four rusts I have found info on three of them and they all have septate spores.
http://www.fieldmycology.net/FRDBI/assoc.asp
http://www.sewbrec.org.uk/content/attachments/Rust%20fungi.pdf.
One further thought; is this one of those species with the potential to produce as many as four different types of spore?
It should be noted the finder was Gordon Beakes (Plankey Mill).
Since John asked me to post this he has reminded me of uredospores. I had mistakenly concentrated on the teliospores.
Of note, no matter how good E&E is it does not list every species recorded on any given plant.