Category: Algae
Phylum: Rhodophyta
Class: Bangiophyceae
Family: Bangiaceae

Notes
In other parts of the world Porphyra has an asexual shell boring generation called a Conchocelis stage. This has not been observed from NZ species. The most commonly seen plantsare foliose, up to 20 cm across, usually in the form of expanded sheets or tufted rosettes. Holdfast is basal rhizoids. Colour is purplish to grey or dull green, texture is firm and glossy, plants are quite tough and not easily torn when mature. Many species throughout NZ, often indistinguishable from each other. Forms rosettes or sheets on rocks, can look like a sheet of plastic draped over the rocks. These are intertidal, but other species are epiphytic and host-specific on larger algae from the low intertidal to the subtidal. All NZ species are only one cell layer thick (monostromatic).
Porphyra is farmed in several countries (mostly in Asia) and is a common ingredient in soups and sushi.

References
Seaweeds of NZ; Adams