The Black Pearl Oyster or Black Pearl King Oyster  is a oyster mushroom (Pleurotus ostreatus) hybrid from Japan. It is the result of a cross between a European and an Asian Pleurotus ostreatus. It grows and looks much like Pleurotus eryngii (King Oyster) in the beginning as it matures it will look more like a Pleurotus ostreatus (Pearl Oyster). Black Pearl Kings are less finicky than Pleurotus eryngii, and are able to grow very well indoors. Grows on the same substrates as pearl or king oysters such as masters mix or hardwood sawdust (HWFP). It is a fast substrate colonizer that fruits dense, meaty mushrooms.
 
Colonization Temperature: 65-78F
Fruiting Conditions:
Temperature: 50-68F
Humidity: 90-95%
Air exchanges: 4-8 per hour
 
Thanks go out Aaron Johnson for some of these pics