Chinese black mushrooms are much like Japanese
shitake mushrooms. I believe that they also grow on rotted tree trunks.
Dried mushrooms are actually much more flavourful than fresh, because the moisture has evaporated, intensifying the flavour. When you reconstitute them, please save the soaking liquer and use it in a broth. Discard (compost or add to a stock) the stems.
When buying Chinese black mushrooms, remember that the finer kind have white splits and cracks. They are rather more expensive but, please, don't be cheap. You are worth taking the time and trouble and expense. After all, what you eat becomes you.