Associated organism genera: Uapaca [2 taxa], Udonga [1 taxon], Ugni [2 taxa], Uleomyces [11 taxa], Ulex [52 taxa], Ullolitsea [1 taxon], Ulmus [1242 taxa], Ulocladium [3 taxa], Ulothrix [1 taxon], Ulva [2 taxa], Umbellularia [1 taxon], Umbilicaria [2 taxa], Umbilicus [5 taxa], Unaspis [6 taxa], Uncaria [13 taxa], Uncinia [33 taxa], Uncinula [8 taxa], Uncinuliella [7 taxa], Ungnadia [3 taxa], Unguiculariopsis [20 taxa], Unguiculella [4 taxa], Uniola [9 taxa], Unona [1 taxon], Unonopsis [1 taxon], Urania [1 taxon], Uraria [14 taxa], Urceola [7 taxa], Urceolella [1 taxon], Urechites [6 taxa], Uredinophila [24 taxa], Uredo [67 taxa], Urelytrum [2 taxa], Urena [40 taxa], Urera [7 taxa], Urginea [22 taxa], Urochloa [153 taxa], Urocystis [2 taxa], Urohendersonia [1 taxon], Uromyces [141 taxa], Urospermum [1 taxon], Urospora [1 taxon], Urostigma [3 taxa], Ursus [4 taxa], Urtica [449 taxa], Urvillea [26 taxa], Usnea [27 taxa], Usteria [1 taxon], Ustilago [6 taxa], Ustulina [11 taxa], Utetheisa [2 taxa], Utharomyces [4 taxa], Utricularia [1 taxon], Uvaria [27 taxa], Uvariodendron [2 taxa]