Fatt choy (Nostoc flagelliforme)

Fatt choy (Nostoc flagelliforme), also known as fa cai, black moss, hair moss or hair weed is a terrestrial cyanobacterium (a type of photosynthetic bacteria) that is used as a vegetable in Chinese cuisine. When dried, it appears like black hair.

Fatt choy is a popular ingredient during Chinese New Year and the word fatt itself means prosperous and choy refers to vegetable.