KEY TO INONOTUS S.L.
1. Hyphal system monomitic throughout; setal hyphae present or absent................................... Inonotus P.Karst.
— Hyphal system dimitic in the tube; setal hyphae absent ................................................................................. 2
2. Context and tube trama dimitic; hymenial setae strongly ventricose and dark; dark line present, soon exposed as a dark crust ............................................................................................ Sclerotus Xavier de Lima, gen. nov.
— Context mono-dimitic; tube trama dimitic; dark line in the context present or absent, if present, bellow the mat/tomentum; hymeniael setae variable, rarely absent ....................................... Sanghuangporus / Tropicoporus
KEY TO INONOTUS IN BRAZIL
1. Any kind of setae absent.............................................................................................................................. 2
— Setae present in hymenium or/and in tube trama ........................................................................................ 8
2. Resupinate species ....................................................................................................................................... 3
— Pileate species .............................................................................................................................................. 4
3. Pores 3-4/mm ........................................................................................................... I. venezuelicus Ryvarden
— Pores 7-8/mm ........................................................................................................... I. costaricensis Ryvarden
4. Pores 7-8/mm ........................................................................................ I. luteoumbrinus (Romell) Ryvarden
— Pores 1-6/mm ............................................................................................................................................. 5
5. Pores irregular, 1-3/mm................................................................................. I. dentatus Decock & Ryvarden
— Pores regular, round to angular.................................................................................................................... 6
6. Basidiospores 7-8 x 6-7 Μm ........................................................................................ I. neotropicus Ryvarden
— Basidiospores up to 6 Μm in longest dimension ........................................................................................... 7
7. Pore surface yellow to rusty brown; basidiospores hyaline to pale yellow........ I. splitgerberi (Mont.) Ryvarden
— Pore surface dull purplish brown; basidiospores rusty brown ............................................. I. porrectus Murrill
8. Tramal setae present; hymenial absent or present......................................................................................... 9
— Tramal setae absent; hymenial present ....................................................................................................... 19
9. Hymenial setae absent ............................................................................................................................... 10
— Hymenial setae present.............................................................................................................................. 13
10. Pores 3-4/mm .................................................................................................. I. patouillardii (Rick) Imazeki
— Pores 7-10/mm ......................................................................................................................................... 11
11. Tramal setae 6-8 Μm wide......................... I. parvisetus V.R.T. Oliveira, Xavier de Lima & Gibertoni, sp. nov.
— Tramal setae wider, up to 35 Μm................................................................................................................ 12
12. Basidioma applanate to slightly convex, brown...................................... I. amazonicus Gibertoni & Ryvarden
— Basidioma trequitreous, yellowish................................................... I. brasiliensis Xavier de Lima & Ryvarden
13. Pileate species ............................................................................................................................................ 14
— Resupinate species ..................................................................................................................................... 17
14. Tramal setae branched ........................................................................................ I. cuticularis (Bull.) P. Karst.
— Tramal setae unbranched ........................................................................................................................... 15
15. Pores 8-10/mm ........................................................................ I. portoricensis (Overh.) Baltazar & Gibertoni
— Pores 2-6/mm ........................................................................................................................................... 16
16. Pores 2-3/mm; basidiospores 6-8.5 Μm long...................................................................... I. rickii (Pat.) Reid
— Pores 4-6/mm; basidiospores 5-6 Μm long......................................................... I. pseudoglomeratus Ryvarden
17. Basidiospores 7-8 Μm long .............................................................................................. I. adnatus Ryvarden
— Basidiospores 8.5-13 Μm long ................................................................................................................... 18
18. Basidiospores 8.5-11.5 Μm long, hymenial setae 33-45 Μm long ............. I. multisetifer Abrahão & Gugliotta
— Basidiospores 10-13 Μm long, hymenial setae 20-32 Μm long ................... I. micantissimus (Rick) Rajchemb.
19. Hymenial setae hooked ............................................................................................................................. 20
— Hymenial setae straight ............................................................................................................................. 21
20. Pileus surface strigose; setae 30-55 Μm long.................................................................. I. fulvomelleus Murrill
— Pileus surface tomentose to glabrous; setae 14-35 Μm long ............................... I. radiatus (Sowerby) P. Karst.
21. Pileus surface adpressed velutinate; pore surface rusty brown....................... I. pseudoradiatus (Pat.) Ryvarden
— Pileus surface scrupose; pore surface yellow .............................................................. I. xanthoporus Ryvarden