Porphyra columbina Montagne Pyropia columbina, Southern laver, karengo in the Māori language and luche in the Spanish language, is a species of edible seaweed traditionally harvested by South Island Māori in New Zealand and Chilote people in Chile.

[1] During World War 2 the Māori Battalion were supplied especially with karengo harvested in New Zealand which they chewed raw while on the march.

It is found around South America from Argentina, Chile and Peru, and around Australia and New Zealand including Macquarie Island.

In Chile the algae are collected from the shore, smoked or cured, then a kind of pressed tortilla is formed, also called "pan de luche" (luche loaf), which are marketed in craft markets in different parts of the country with greater emphasis on the South of Chile.

This seaweed is used for the preparation of stews and casseroles, being famous in the country the dish known as cazuela chilota, a soup with Southern laver, potatoes and pieces of lamb.