Kingdom: Fungi
Division: Basidiomycota
Class: Agaricomycetes
Order: Agaricales
Family: Pleurotaceae
Genus: Pleurotus
Species: P. pulmonarius
Binomial name: Pleurotus pulmonarius
Synonyms: Agaricus pulmonarius, Dendrosarcus pulmonarius, Pleurotus ostreatus f. pulmonarius, Pleurotus ostreatus var. pulmonarius, Pleurotus araucariicola.
Common names: Oyster mushroom, Phoenix mushroom, Indian oyster, Grey oyster, Phoenix-tail, Italian Oyster, Phoenix, Lung oyster, Fèngweigu.

Pleurotus pulmonarius is a saprobic species of gilled mushrooms that is widespread in temperate and subtropical forests throughout the world. Its pileus (cap) is >20+cm wide and is convex, becoming broadly convex to flat. The gills are broadly attached and extend down the stipe which is offset from the centre of the pileus.

Pleurotus pulmonarius is one of the commonest cultivated edible mushrooms in the world and now grown commercially in New Zealand. It is sold here as “Oyster mushrooms”. In New Zealand, this exotic mushroom has been reported growing wild near some urban areas. 
Cultivation of oyster mushrooms Pleurotus pulmonarius and Pleurotus ostreatus began in New Zealand in 1994. Previously, quarantine restrictions prevented people from importing spawn. Oyster mushrooms are raised on bags of pasteurised straw, and on sawdust blocks. These large fan-shaped fungi are relatively easy to grow. They are mild-tasting and readily absorb other flavours.

Overseas there another Pleurotus species, Pleurotus eryngii (King oyster mushroom) which is a highly prized delicacy but is not grown here in New Zealand as unlike most of the Pleurotus species, which only colonise dead tissues, Pleurotus eryngii can grow as a parasite on living plants. Pleurotus eryngii spawn cannot be imported as it is listed as an unwanted organism in the Hazardous Substances and New Organism Act 1996. 

Below is an incident report on an attempt to import Pleurotus eryngii spawn into New Zealand.


Cultivated Pleurotus pulmonarius.
[1]

Immature Pleurotus pulmonarius 
[2]  

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/