Key to the eight species of Irpex known from China. The new species is in bold.

1. Basidioma resupinate to effused-reflexed ..........................................................................................................................................2

1. Basidioma resupinate..........................................................................................................................................................................5

2. Hymenium strictly hydnoid........................................................................................................................................ Irpex hydnoides

2. Hymenium first poroid, but soon becoming hydnoid.........................................................................................................................3

3. Basidiospores <2.5 μm in width..................................................................................................................................... Irpex lacteus

3. Basidiospores> 2.5 μm in width........................................................................................................................................................4

4. Pores 1–3 per mm; basidiospores 3–4.5 μm wide ............................................................................................................ Irpex flavus

4. Pores 1–2 per mm; basidiospores 2.8–3.4 μm wide..................................................................................................... Irpex vellereus

5. Hymenial surface smooth.................................................................................................................................................... Irpex lenis

5. Hymenium poroid or irpicoid.............................................................................................................................................................6

6. Pores> 3 per mm..................................................................................................................................................... Irpex jinshaensis

6. Pores <3 per mm................................................................................................................................................................................7

7. Pores 1–3 per mm; basidiospores 3.5–5 × 2–3 μm ..................................................................................................... Irpex laceratus

7. Pores 1–2 per mm; basidiospores 4–5 × 2–2.5 pm...................................................................................................... Irpex subulatus