| Idriella acerosa |
MycoBank | / Index Fungorum | - | |
| Idriella australiensis |
MycoBank | / Index Fungorum | - | |
| Idriella cagnizarii |
MycoBank | / Index Fungorum | - | |
| Idriella couratarii |
MycoBank | / Index Fungorum | - | |
| Idriella cubensis |
MycoBank | / Index Fungorum | - | |
| Idriella desertorum |
MycoBank | / Index Fungorum | - | |
| Idriella fertilis |
MycoBank | / Index Fungorum | - | |
| Idriella jambosae |
MycoBank | / Index Fungorum | - | |
| Idriella lunata |
MycoBank | / Index Fungorum | - | |
| Idriella mycogonoidea |
MycoBank | / Index Fungorum | - | |
| Idriella ramosa |
MycoBank | / Index Fungorum | - | |
| Idriella rara |
MycoBank | / Index Fungorum | - | |
| Idriella setiformis |
MycoBank | / Index Fungorum | - | |
| Idriella taiwanensis |
MycoBank | / Index Fungorum | - | |
| Idriella tropicalis |
MycoBank | / Index Fungorum | - | |
| Idriella uncinospora |
MycoBank | / Index Fungorum | - | |
| Idriella variabilis |
MycoBank | / Index Fungorum | - | |
| Igneocumulus yuccae |
MycoBank | / Index Fungorum | - | |
| Ijuhya chilensis |
MycoBank | / Index Fungorum | - | |
| Ijuhya corynespora |
MycoBank | / Index Fungorum | - | |
| Ijuhya dentifera |
MycoBank | / Index Fungorum | - | |
| Ijuhya peristomialis |
MycoBank | / Index Fungorum | - | |
| Ileodictyon cibarium |
MycoBank | / Index Fungorum | / Genbank | |
| Illosporium olivatrum |
MycoBank | / Index Fungorum | - | |
| Immersiella caudata |
MycoBank | / Index Fungorum | / Genbank | |
| Incrucipulum ciliare |
MycoBank | / Index Fungorum | - | |
| Incrustoporia nivea |
MycoBank | / Index Fungorum | - | |
| Incrustoporia semipileata |
MycoBank | / Index Fungorum | - | |
| Incrustoporia stellae |
MycoBank | / Index Fungorum | - | |
| Incrustoporia subincarnata |
MycoBank | / Index Fungorum | - | |
| Induratia apiospora |
MycoBank | / Index Fungorum | - | |
| Infundibura adhaerens |
MycoBank | / Index Fungorum | / Genbank | |
| Ingoldia entomobryoides |
MycoBank | / Index Fungorum | - | |
| Ingoldia tricapillata |
MycoBank | / Index Fungorum | - | |
| Ingoldiella fibulata |
MycoBank | / Index Fungorum | - | |
| Ingoldiella hamata |
MycoBank | / Index Fungorum | - | |
| Inifatiella nectandrae |
MycoBank | / Index Fungorum | - | |
| Inocutis dryophila |
MycoBank | / Index Fungorum | - | |
| Inocutis rheades |
MycoBank | / Index Fungorum | / Genbank | |
| Inocutis tamaricis |
MycoBank | / Index Fungorum | / Genbank | |
| Inocybe asterospora |
MycoBank | / Index Fungorum | / Genbank | |
| Inocybe brevispora |
MycoBank | / Index Fungorum | - | |
| Inocybe maculata |
MycoBank | / Index Fungorum | / Genbank | |
| Inocybe rimosa |
MycoBank | / Index Fungorum | / Genbank | |
| Inocybe sp. |
MycoBank | / Index Fungorum | - | |
| Inocybe umbrina |
- | - | / Genbank | |
| Inonotus andersonii |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus circinatus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus cuticularis |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus dryadeus |
MycoBank | / Index Fungorum | - | |
| Inonotus dryophilus |
MycoBank | / Index Fungorum | - | |
| Inonotus flavidus |
MycoBank | / Index Fungorum | - | |
| Inonotus glomeratus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus hispidus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus iodinus |
MycoBank | / Index Fungorum | - | |
| Inonotus leporinus |
MycoBank | / Index Fungorum | - | |
| Inonotus ludovicianus |
MycoBank | / Index Fungorum | - | |
| Inonotus mikadoi |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus nidus-pici |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus nodulosus |
MycoBank | / Index Fungorum | - | |
| Inonotus nothofagi |
MycoBank | / Index Fungorum | - | |
| Inonotus obliquus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus pachyphloeus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus patouillardii |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus porrectus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus radiatus |
MycoBank | / Index Fungorum | - | |
| Inonotus radiatus var. cephalantii |
- | - | - | |
| Inonotus radiatus var. nodulosus |
MycoBank | / Index Fungorum | - | |
| Inonotus radiatus var. radiatus |
- | - | - | |
| Inonotus radiatus var. rheades |
- | - | - | |
| Inonotus rheades |
MycoBank | / Index Fungorum | - | |
| Inonotus rickii |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus rodwayi |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus setiporus |
MycoBank | / Index Fungorum | - | |
| Inonotus sp. |
MycoBank | / Index Fungorum | - | |
| Inonotus splitgerberi |
MycoBank | / Index Fungorum | - | |
| Inonotus tabacinus |
MycoBank | / Index Fungorum | - | |
| Inonotus tamaricis |
MycoBank | / Index Fungorum | - | |
| Inonotus tomentosus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus weirianus |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus weirii |
MycoBank | / Index Fungorum | / Genbank | |
| Inonotus xeranticus |
MycoBank | / Index Fungorum | / Genbank | |
| Intercalarispora nigra |
MycoBank | / Index Fungorum | - | |
| Iodophanus carneus |
MycoBank | / Index Fungorum | / Genbank | |
| Iodophanus testaceus |
MycoBank | / Index Fungorum | / Genbank | |
| Irenina ugandensis |
MycoBank | / Index Fungorum | - | |
| Irpex brevis |
MycoBank | / Index Fungorum | - | |
| Irpex cinnamomeus |
MycoBank | / Index Fungorum | - | |
| Irpex consors |
MycoBank | / Index Fungorum | - | |
| Irpex discolor |
MycoBank | / Index Fungorum | - | |
| Irpex flavus |
- | - | - | |
| Irpex fuscoviolaceus |
MycoBank | / Index Fungorum | - | |
| Irpex lacteus |
MycoBank | / Index Fungorum | / Genbank | |
| Irpex mollis |
MycoBank | / Index Fungorum | - | |
| Irpex nothofagi |
- | - | - | |
| Irpex obliquus |
MycoBank | / Index Fungorum | - | |
| Irpex parvulus |
MycoBank | / Index Fungorum | - | |
| Irpex pendulus |
MycoBank | / Index Fungorum | - | |
| Irpex vellereus |
MycoBank | / Index Fungorum | / Genbank | |
| Irpicodon pendulus |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria atypicola |
MycoBank | / Index Fungorum | - | |
| Isaria cateniannulata |
MycoBank | / Index Fungorum | - | |
| Isaria cateniobliqua |
MycoBank | / Index Fungorum | - | |
| Isaria cicadae |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria coleopterorum |
MycoBank | / Index Fungorum | - | |
| Isaria cretacea |
MycoBank | / Index Fungorum | - | |
| Isaria farinosa |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria felina |
MycoBank | / Index Fungorum | - | |
| Isaria fumosorosea |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria ghanensis |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria japonica |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria javanica |
MycoBank | / Index Fungorum | / Genbank | |
| Isaria psychidae |
MycoBank | / Index Fungorum | - | |
| Isaria sinclairii |
MycoBank | / Index Fungorum | - | |
| Isaria sp. |
MycoBank | / Index Fungorum | - | |
| Isaria sulfurea |
MycoBank | / Index Fungorum | - | |
| Isaria tenuipes |
MycoBank | / Index Fungorum | / Genbank | |
| Ischnoderma benzoinum |
MycoBank | / Index Fungorum | / Genbank | |
| Ischnoderma resinosum |
MycoBank | / Index Fungorum | / Genbank | |
| Isoachlya intermedia |
MycoBank | / Index Fungorum | - | |
| Isoachlya itoana |
MycoBank | / Index Fungorum | - | |
| Isoachlya subterranea |
MycoBank | / Index Fungorum | - | |
| Isoachlya toruloides |
MycoBank | / Index Fungorum | - | |
| Isoachlya unispora |
MycoBank | / Index Fungorum | - | |
| Issatchenkia hanoiensis |
MycoBank | / Index Fungorum | / Genbank | |
| Issatchenkia occidentalis |
MycoBank | / Index Fungorum | - | |
| Issatchenkia orientalis |
MycoBank | / Index Fungorum | - | |
| Issatchenkia scutulata |
MycoBank | / Index Fungorum | / Genbank | |
| Issatchenkia scutulata var. exigua |
MycoBank | / Index Fungorum | - | |
| Issatchenkia scutulata var. scutulata |
MycoBank | / Index Fungorum | - | |
| Issatchenkia sp. |
MycoBank | / Index Fungorum | - | |
| Issatchenkia sp. var. scutulata |
- | - | - | |
| Issatchenkia terricola |
MycoBank | / Index Fungorum | / Genbank | |
| Isthmolongispora ampulliformis |
MycoBank | / Index Fungorum | / Genbank | |
| Isthmolongispora lanceata |
MycoBank | / Index Fungorum | - | |
| Isthmolongispora minima |
MycoBank | / Index Fungorum | / Genbank | |
| Isthmolongispora quadricellularia |
MycoBank | / Index Fungorum | - | |
| Isthmolongispora quadricellularis |
MycoBank | / Index Fungorum | - | |
| Isthmolongispora variabilis |
MycoBank | / Index Fungorum | - | |
| Isthmotricladia laeensis |
MycoBank | / Index Fungorum | - | |
| Itersonilia pastinacae |
MycoBank | / Index Fungorum | / Genbank | |
| Itersonilia perplexans |
MycoBank | / Index Fungorum | / Genbank | |
| Itersonilia pyriformis |
MycoBank | / Index Fungorum | / Genbank | |
| Iwilsoniella ovalis |
- | - | - | |