XVI International Botanical Congess

The total number of Uromyces species recorded from Ukraine is 76, a clear indication that rust fungi of this country have already received considerable attention. In comparison, in Poland, Uromyces is represented by 62 species (Majewski, 1977), and by 33 species in Norway (Jorstad, 1964). These figures may reflect a general tendency for biodiversity to increasing towards the equator. Interestingly, within individual defined areas, the percentage of Uromyces species among the rusts as a whole also increases southwards: Norway (14.3%), Poland (21.0%), Ukraine [forest-steppe zone] (21.8%), Ukraine [steppe zone] (24.4%), and these statistics can be interpreted as confirmation of the hypothesis by Leppik (1972) that Uromyces originated near the ancient Tethys ocean.