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.