Kombu

The pronunciation of 綸 is 関 (gūan), meaning cord made by green thread, and got corrupted to 昆 (kūn).Another possibility to explain the association arises because descriptions of kūnbù in Chinese documents are vague and inconsistent, and it is impossible to identify to which seaweed the term might have applied.

Moreover, following Zhang Yxi, Li Shizhen classified kūnbù and haidai (stands for kombu in Chinese) as different things,[10] and this classification continues in China today.

As to surviving documents, the letters 軍布 (in Sino-Japanese reading 軍 is gun/kun; 布 is fu/pu/bu) appeared in Man'yōshū and wood strips from Fujiwara-kyō, and may have indicated kombu.

The Shoku Nihongi (797) reports: in 797 Suga no Komahiru [ja] of Emishi (Ainu or Tohoku region people) stated they had been offering up kombu, which grew there, as tribute to the Yamato court every year without fail.

[citation needed] During the Muromachi period, a newly developed drying technique allowed kombu to be stored for more than a few days, and it became an important export from the Tohoku area.

[citation needed] By the Edo period, as Hokkaidō was colonized and shipment routes were organized, the use of kombu became widespread throughout Japan.

Traditional Okinawan cuisine relies heavily on kombu as a part of the diet; this practice began in the Edo period.

[14][15] He found that glutamic acid was responsible for the palatability of the dashi broth created from kombu, and was a distinct sensation from sweet, sour, bitter, and salty tastes.

The softened kombu is commonly eaten after cooking or is sliced and used to make tsukudani, a dish that is simmered in soy sauce and mirin.

Algae including kombu also contain entire families of obscure enzymes that break down complex sugars that are normally indigestible to the human gut (thus gas-causing).

[21] Genetically manipulated E. coli bacteria can digest kombu into ethanol, making it a possible maritime biofuel source.