Zi Cai

Zi Cai refers to the dried thalli of marine red algae of the genus Porphyra (Bangiaceae), principally Porphyra tenera and P. haitanensis, cultivated along the coasts of China, Korea and Japan. The thallus is a thin, membranous blade one or two cell layers thick, ovate to lanceolate, with frilled or smooth margins, typically 10–30 cm long and varying in colour from purplish-red to brownish-black when dried in sheets. It attaches to rocky intertidal substrates by a small holdfast. Reproduction alternates between the foliose gametophyte and a filamentous conchocelis stage that bores into mollusc shells. As an algal organism, it is not a vascular plant.