Géneros de hongos: Uberispora [3 taxones], Uleiella [4 taxones], Uleodothis [6 taxones], Uleomyces [10 taxones], Uleopeltis [1 taxon], Uleothyrium [1 taxon], Ulocladium [97 taxones], Ulocolla [1 taxon], Umbellidion [15 taxones], Umbellula [3 taxones], Umbelopsis [8 taxones], Umbilicaria [2 taxones], Uncinia [2 taxones], Uncinula [703 taxones], Uncinuliella [102 taxones], Underwoodia [10 taxones], Unguicularia [17 taxones], Unguiculariopsis [16 taxones], Unguiculella [38 taxones], Ungulina [9 taxones], Uraecium [3 taxones], Urceolella [10 taxones], Uredinella [2 taxones], Uredinophila [21 taxones], Uredinopsis [32 taxones], Uredo [1602 taxones], Uredopeltis [1 taxon], Urnula [15 taxones], Urocystis [197 taxones], Urohendersonia [8 taxones], Uromyces [7369 taxones], Uromycladium [1 taxon], Urophlyctis [2 taxones], Uropyxis [40 taxones], Urospora [1 taxon], Urosporella [1 taxon], Urosporellopsis [1 taxon], Usnea [621 taxones], Ustalia [1 taxon], Ustilaginoidea [77 taxones], Ustilago [1817 taxones], Ustulina [153 taxones], Utharomyces [4 taxones], Uthatobasidium [1 taxon], Uvarispora [1 taxon]