Thanks for your sharing.I hope your knowledge of basidiomycetes made your trip more interesting.

Oyster mushroom, also known as Pleurotus ostreatus, is an edible mushroom. It has a broad, fan or oyster-shaped cap and also white or cream gills. These fungi usually grow near trees and they are very easy to cultivate so they are very common food especially in Asian countries.

Yes, the oyster mushroom is an edible basidiomycete which is commonly cultivated among Asian countries. Besides, the oyster mushrooms are predaceous that they can eat nematodes by secreting anaesthetic chemicals from their hyphae to trap the nematodes. Then the fungal hyphae will penetrate the nematodes and digest them. This behaviour can be observed when the level of nitrogen in the wood substrate is low.

thanks for your additional info.

Oyster mushrooms are saprobic and sometimes weakly parasitic. The mycelia of oyster mushrooms obtains nitrogen by actively hunting for nematodes, which are microscopic worm-like organisms, within its substrate. It captures and paralyses them, then probes into the still-living creature’s mouth before releasing proteins that digest it from the inside out. Q) Are there any other ecological roles of the oyster mushrooms?

Ching Tung: Thanks for your sharing. Can I know the source of your information? Do oyster mushrooms refer to a single species or a group of mushrooms?

Though we can only see the top of the pileus, we can find that the pileus is parallel to the ground, and vertically orientated gills can help the spread of spores.
We know both stipe and gills of the fruiting bodies of some Basidiomycota have gravitropism, and in the picture, though the fruiting body grew from the surface of the substrate that perpendicular to the ground, finally the pilei are still parallel to the ground.
And in nature, oyster mushrooms often grow on the trunks, parasitic on rotting wood, and gravitropism can really help them to spread spores.