Irpiciporus

Regio, Nicolas Do Carmo, Westphalen, Mauro C. & Silveira, Rosa Mara Borges Da, 2024, Studies on Neotropical Cerrenaceae (Basidiomycota, Polyporales): a new species of Irpiciporus from Brazil, Phytotaxa 675 (3), pp. 217-232 : 227

Key to the known species of Irpiciporus (adapted from Nakasone & Ortiz-Santana 2022)

1. Basidiomes resupinate........................................................................................................................................................................2

- Basidiomes pileate, effused-reflexed to sessile ..................................................................................................................................5

2. Hymenophore irpicoid to labyrinthine, spines up to 10 mm long, basidia 30–40 µm long, basidiospores 5–7 × 4.5–6 µm, from Europe............................................................................................................................................................................. I. pachyodon

- Spines up to 6 mm long, basidiospores up to 5 µm wide, Neotropical species .................................................................................3

3. Basidiospores <3.5 µm diam ......................................................................................................................................... I. decolorans

- Basidiospores typically> 3.5 µm diam ..............................................................................................................................................4

4. Hymenophore spinose to sublamellate (when young), basidia 18–22 µm long, basidiospores 4–5 × 3.6–4.3 µm ........ I. revolubilis

- Hymenophore spinose, basidia 25–40 µm long, basidiospores 5–6 × 4–5 µm, prismatic crystals throughout the context and teeth trama............................................................................................................................................................................ I. rajchenbergii

5. Hymenophore poroid..........................................................................................................................................................................6

- Hymenophore hydnoid to irpicoid......................................................................................................................................................7

6. Pileus surface silky, basidiospores 4.3–5 × 3.9–4.3 µm, Neotropical species .................... Irpiciporus sp. (cf. Tyromyces irpiceus );

- Basidiomes pileate and solitary, hymenophore with sinuous pores, basidia 17–23 µm long, basidiospores 5–6 × 4–5 µm, from China.................................................................................................................................................................................... I. sinuosus

7. Hymenophore spinose even near the margins, basidia 16.5–23 µm long; prismatic crystals throughout the context and teeth trama; Brazilian species............................................................................................................................................................ I. prismaticus

- Hymenophore irpicoid to spinose with incomplete pores near the margins; basidia larger, 30–40 µm long, or unknown, from Africa, North America or Europe .......................................................................................................................................................8

8. Basidiomes thin and fragile, pores/spines densely arranged, 2–3 per mm, basidiospores 4.5–6 × 4–5 µm, from Eastern Africa ...... .................................................................................................................................................................................... I. branchiformis

- Basidiomes thicker, pores/spines sparser, 0.5–2 per mm, basidiospores larger, distributed in the Northern Hemisphere ................9

9. Basidiomes sessile to effused-reflexed, hymenophore irpicoid to labyrinthine, basidiospores 5–6 × 4.3–5.3 µm (Qm = 1.13), from North America ......................................................................................................................................................................... I. mollis

- Basidiomes generally effused-reflexed with imbricate pilei, hymenophore irpicoid to spinose, basidiospores slightly larger 5–7 × 4.5–5.6 µm (Qm = 1.18), from Europe ........................................................................................................................... I. pachyodon