Nationally Critical
The Department of Conservation 'Nationally Critical' category of rare and threatened species is defined as:
"A taxon is Nationally Critical when available scientific evidence indicates that it meets any of the following three criteria:
- The total population size is <250 mature individuals.
- Human influences have resulted in <2 sub-populations, and either <200 mature individuals in the largest sub-population, or, the total area of accupancy is <1 ha.
- There is a predicted decline of >80% in the total population in the next 10 years due to existing threats."
The species in this table all have large, easily collected, and distinctive fruiting bodies, hence excluding most micro-fungi This bias reflects the limitations of current knowledge of micro-fungi.
| Fungus Name | Link to NZFUNGI database | Collections in Herb. PDD | Rarity assessment | Recorded from 1 or more Crosby district |
| Austrogaster novaezelandiae |  |
0 | Nationally Critical | 1 |
| Berggrenia cyclospora | |
1 | Nationally Critical | 1 |
| Cantharellus elsae | |
0 | Nationally Critical | 1 |
| Chlorovibrissea bicolor | |
1 | Nationally Critical | 1 |
| Chlorovibrissea melanochlora | |
1 | Nationally Critical | 1 |
| Chlorovibrissea tasmanica | |
1 | Nationally Critical | 1 |
| Claustula fischeri | |
1 | Nationally Critical | 1 |
| Cordierites acanthophora | |
3 | Nationally Critical | 1 |
| Ganoderma sp. | 3 | Nationally Critical | 1 | |
| Gomphus dingleyae | |
1 | Nationally Critical | 1 |
| Gomphus novaezelandiae | |
1 | Nationally Critical | 1 |
| Gyroporus castaneus | |
3 | Nationally Critical | 1 |
| Hysterangium youngii | |
1 | Nationally Critical | 1 |
| Lactarius maruiaensis | |
1 | Nationally Critical | 1 |
| Phanerochaete citrina | |
1 | Nationally Critical | 1 |
| Phanerochaete corymbata | |
1 | Nationally Critical | 1 |
| Phanerochaete luteoaurantiaca | |
1 | Nationally Critical | 1 |
| Polyporus septosporus | |
3 | Nationally Critical | 1 |
| Puccinia embergeriae | |
3 | Nationally Critical | 1 |
| Puccinia freycinetiae | |
1 | Nationally Critical | 1 |
| Ramaria aureorhiza | |
1 | Nationally Critical | 1 |
| Ramaria avellaneovertex | |
1 | Nationally Critical | 1 |
| Ramaria basirobusta | |
1 | Nationally Critical | 1 |
| Ramaria junquilleovertex | |
1 | Nationally Critical | 1 |
| Ramaria piedmontiana | |
1 | Nationally Critical | 1 |
| Ramariopsis avellanea | |
1 | Nationally Critical | 1 |
| Ramariopsis avellaneoinversa | |
1 | Nationally Critical | 1 |
| Ramariopsis tortuosa | |
1 | Nationally Critical | 1 |
| Russula inquinata | |
2 | Nationally Critical | 1 |
| Russula littoralis | |
2 | Nationally Critical | 1 |
| Russula miniata | |
1 | Nationally Critical | 1 |
| Russula papakaiensis | |
2 | Nationally Critical | 1 |
| Russula pleurogena | |
0 | Nationally Critical | 1 |
| Russula solitaria | |
1 | Nationally Critical | 1 |
| Squamanita squarrulosa | |
2 | Nationally Critical | 1 |
| Thaxterogaster cartilagineus | |
1 | Nationally Critical | 1 |
| Uredo chathamica | |
6 | Nationally Critical | 1 |
| Volvariella surrecta | |
1 | Nationally Critical | 1 |
| Xylaria wellingtonensis | |
1 | Nationally Critical | 1 |
| Xylaria zealandica | |
1 | Nationally Critical | 1 |
| Chalciporus aurantiacus | |
0 | Nationally Critical | >1 |
| Colpoma nothofagi | |
2 | Nationally Critical | >1 |
| Dichomitus newhookii | |
2 | Nationally Critical | >1 |
| Inonotus chondromyelus | |
3 | Nationally Critical | >1 |
| Phallobata alba | |
3 | Nationally Critical | >1 |
| Russula vivida | |
1 | Nationally Critical | >1 |
| Sarcosoma orientale | |
1 | Nationally Critical | >1 |
| Undescribed genus (Trichocomaceae) | 2 | Nationally Critical | >1 | |
| Uredo salicorniae | |
2 | Nationally Critical | >1 |