PUCCINIA DISTINCTA, CAUSE OF THE CURRENT DAISY RUST EPIDEMIC IN BRITAIN, IN COMPARISON WITH OTHER RUSTS RECORDED ON DAISIES, P-OBSCURA AND P-LAGENOPHORAE

Three British rust fungi reported to form aecia on daisy (Bellis peren nis) are compared. A recently discovered species, possibly introduced from Australia, is identified as Puccinia distincta. It is a short-cyc led -opsis form lacking uredinia, with aecia and telia confined to Bel lis and its aeciospores capable of reinfecting the same host. This rus t is compared with a macrocyclic heteroecious eu-form, P. obscura, whi ch produces pycnia and aecia on Bellis and uredinia and telia on Luzul a. Puccinia distincta is probably derived from and correlated with P. obscura because both species have the same aecial host, and because th eir teliospores are closely similar in morphology and dimensions. Comp arison is extended to P. lagenophorae, a common rust with aecia and te lia on Senecio spp., which has been reported to form aecia on Bellis f ollowing inoculation with aeciospores from Senecio. The repeated failu re of our own reciprocal inoculation experiments using aeciospores fro m the two different hosts and differences in teliospore morphology bet ween P. distincta and P. lagenophorae lead us to conclude that the cur rent rust epidemic on daisies is caused by P. distincta which is disti nct from P. lagenophorae.