Fa Chai 发菜 (black moss) contain no nutritional value, it has been found to contain a toxic amino acid linked to degenerative diseases affecting the normal functions of nerve cells, such as Alzheimer’s disease, Parkinson’s disease and dementia. Check out this link.
I just trashed a bag of Fa Chai. Felt sad because it was not cheap. But, I did get a chance to take a photo and posted it here.
(Little Corner of Mine, thanks again for the info and link.)