Nostoc flagelliforme was first recorded in Li Yu's Casual Notes in Qing Dynasty (161-about 1679). "The dishes with the strangest hue are not recorded in the books of Materia Medica and Foodstuffs, so the hair dishes produced in the Western Qin Dynasty are also soaked." It is said that Nostoc flagelliforme was an export material in the Tang and Song Dynasties.
Extended data:
Characteristics of Nostoc flagelliforme:
Nostoc flagelliforme, a terrestrial algae in the genus Nostoc of Nostoc of Cyanophyta. The cells are all black and blue. Edible Nostoc flagelliforme is attached to the bottom of desert plants. Because of its messy hair and dark color, it is named Nostoc flagelliforme, which is also called "ground hair".
The algae body is hairy, straight or curved, brown, and brown-black after drying. Often, many algae bodies are wound into a ball, and the maximum diameter of the ball is 0. 5 meters. The width of a single algae body is 0. 3 ~ 0.51mm when it is dried, and it is sticky and elastic after absorbing water, and its diameter can reach 1. 2 mm..
Source of reference: Baidu Encyclopedia-Nostoc flagelliforme