Key to the known Spodocybe species in the world

1. Pileus medium-sized, the diameter usually 30–80 mm ......................................................................................................................2

- Pileus small-sized, the diameter usually 10–30 mm ..........................................................................................................................3

2. Lamellae crowded; flesh without a smell of cyanide ....................................................................................................... S. herbarum

- Lamellae distant; flesh with a smell of cyanide ............................................................................................................... S. cyanolens

3. Basidia 2-spored .................................................................................................................................................................. S. bispora

- Basidia 4-spored .................................................................................................................................................................................4

4. Lamellae with abundant furcation..................................................................................................................................... S. fontqueri

- Lamellae without or with a few furcation ..........................................................................................................................................5

5. Pileus smooth and glabrous................................................................................................................................................... S. collina

- Pileus not smooth, surface finely tomentose, felty or rugose.............................................................................................................6 6. Pileus finely tomentose.......................................................................................................................................................................7

- Pileus finely felty or rugose................................................................................................................................................................8

7. Basidiospores 3.3–4.9 × 2.2–3.8 μm, broadly ellipsoid to ellipsoid ............................................................................... S. tomentosa

- Basidiospores 5.5–7.5 × 3.0–4.0 μm, elongate.............................................................................................................. S. trulliformis

8. Pileus finely felty; basidiospores 6.0–9.0 × 3.0–4.5 μm; pileipellis with outgrowths and branches .............................. S. umbilicata

- Pileus rugose; basidiospores 5.0–6.0 × 3.0–3.5 μm; pileipellis without outgrowths and branches ............................... S. rugosiceps