Key to all species of Neohygrocybe worldwide

including ones named in Hygrocybe

1. Lamellae changing colour when bruised (pink, red, brown or black)................................................................................................2

1’. Lamellae not changing colour with bruising......................................................................................................................................7

2. Lamellae at least initially bruising pink, red or reddish brown..........................................................................................................3

2’. No pink or red bruising reactions, but may bruise directly to brown or black...................................................................................6

3. Pileus and stipe dark greyish brown; odour not distinctive................................................................................................................4

3’. Pileus and stipe usually paler, pale drab grey or pale reddish brown; odour often distinct ...............................................................5

4. Basidiomes large, 30–35 mm; basidiospores 7–9 µm long, subtropical China ............................................................ N. griseonigra

4’. Basidiomes smaller, 20–25 mm; basidiospores 6–7.5 µm long; in Australia ............................................................... N. lawsonensis

5. Odor fruity or fragrant; basidiospores subglobose, 5–7 × 5–6 µm, E. North America and Puerto Rico, Caribbean........ N. subovina

5’. Odour alkaline; basidiospores larger and ellipsoid, 7–8.5 × 4.5–5 µm, New Zealand ......................................................... N. innata

6. Pileus large, 20–90 mm, margin dark; basidospores 7–9.5 µm long; pseudocystidia absent; odour unpleasant or nitrous; Europe and E. North America.................................................................................................................................................................... N. ovina

6’. Pileus smaller, with a pale grey margin; basidiospores shorter, 5.5–8 µm long; large pseudocystidia present; odour absent; Puerto Rico, Caribbean ............................................................................................................................................................... N. ovinoides

7. Odour none .........................................................................................................................................................................................8

7’. Odour unpleasant, nitrous or farinaceous.........................................................................................................................................11

8. Large pseudocystidia absent in hymenium; pileipellis terminal hyphal elements swollen, subclavate to subglobose; in Australia ... ...................................................................................................................................................................... Hygrocybe badioclavata

8’. Characters different, large pseudocystidia present; pileipellis hyphal ends not swollen ...................................................................9

9. Pileus vinaceous brown, pale margin, small (2–8 mm); Caribbean ........................................................... Hygrocybe albomarginata

9’. Pileus grey-brown to black, lacking a pale band on margin large (20-45 mm); South Pacific........................................................10

10. Spores small, 6.5–7.5 × 4.5–5.5 µm; in New Zealand .................................................................................................... N. squarrosa 10’. Spores larger, 7–9.5 × 5.5–7 µm; in Hawaii......................................................................................................... Hygrocybe waolipo

11. Large pseudocystidia present in hymenium .....................................................................................................................................12

11’. Pseudocystidia absent in hymenium.................................................................................................................................................13

12. Stipe slender, 5–7 mm wide; pileipellis hyphae encrusted; Brazil ...................................................................................... N. fumosa

12’. Stipe swollen, 8–32 mm wide; pileipellis hyphae not encrusted; Europe................................................................ N. pseudoingrata

13. Pileus sooty brown; odour farinaceous; in Australia ........................................................................... Hygrocybe fuligineosquamosa

13’. Pileus warmer colour, grey- orange- or golden-brown; odour nitrous .............................................................................................14

14. Pileus perforated in centre; in Sri Lanka, India .............................................................................................. Hygrocybe cinerascens

14’. Pileus not perforated in centre; in Europe, Iceland .............................................................................................................. N. nitrata