Fat choy

Fat choy, Nostoc flagelliforme, also known as faat choy, 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, the product has the appearance of black hair. For that reason, its name in Chinese means "hair vegetable". When soaked, this vegetable has a very soft texture which is like very fine vermicelli, and an appearance very similar to long, black human hair.

Production
Fat choy grows on the ground in the Gobi Desert and the Qinghai plateau. Over-harvesting on the Mongolian steppes has furthered erosion and desertification in those areas. The Chinese government has limited its harvesting, which has caused its price to increase. This may be one reason why some commercially available fat choy has been found to be adulterated with strands of a non-cellular starchy material, with other additives and dyes. Real fat choy is dark green in color, while the counterfeit fat choy appears black.

Chinese culture
The last two syllables of this name in Cantonese sound the same as another Cantonese saying meaning "struck it rich" (though the second syllable, choi, has a different tone) -- this is found, for example, in the Cantonese saying, "Gung1 hei2 faat3 choi4" (恭喜发财, meaning "congratulations and be prosperous"), which is often proclaimed during Chinese New Year. For that reason, this product is a popular ingredient in dishes used for the Chinese New Year. It is enjoyed as an alternative to cellophane noodles. It is mostly used in Cantonese cuisine and Buddhist cuisine. It is sometimes used as a hot pot ingredient.

Health effects
A research team from the biochemistry department of the Chinese University of Hong Kong said that international research has shown that fat choy, besides having no nutritional value, has also been found to contain Beta-methylamino L-alanine (BMAA), a toxic amino acid that could affect the normal functions of nerve cells. Professor Chan King-ming of the team told the media that eating fat choy could lead to degenerative diseases such as Alzheimer's, Parkinson's, and dementia.