Key-thorn seaweed - Key-thorn seaweed

Japanese: カギイバラノリ - かぎいばらのり

...Most species grow 10-20cm tall, but some species grow even taller. More than 10 species grow off the coast of Japan alone, and some of the more common species include H. charoides Lamour, H. saidana Holmes, H. variabilis Okamura, and H. japonica Tanaka. H. charoides grows irregularly, while H. variabilis grows horizontally and H. variabilis has a flat stem and branches horizontally only at the top.

From [Egonori]

...The thinly poured and solidified seaweed is cut into strings and eaten with vinegar and soy sauce. A similar seaweed is the thorny algae Porphyra arborescens, which grows by wrapping itself around sargassum species, but it is easily distinguished by the fact that the tip does not branch out regularly and that the body does not have the joint structure reminiscent of the segments of an earthworm. [Chihara Mitsuo]...

*Some of the terminology that refers to "Kagiibara Nori" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…高さは10～20cmのものが多いが，さらに大きくなる種類もある。日本沿岸だけでも10種以上が生育し，よく見られる種類として，イバラノリH.charoides Lamour.，サイダイバラH.saidana Holmes，タチイバラH.variabilis Okamura，カギイバラノリH.japonica Tanakaなどがある。イバラノリは枝を不規則に出すが，サイダイバラは小枝を水平に出し，タチイバラは茎が扁平で上方でのみ枝を水平に出す。…