The identity of the carrageenophyte red alga Sarcothalia radula (Gigartinaceae, Rhodophyta)

Abstract

AbstractThe carrageenophyte red alga Sarcothalia radula (Gigartinaceae), referred to under its earlier name Gigartina radula, is one of eight species considered a safe source of the refined hydrocolloid and food additive carrageenan and is also reported to be a source of compounds of interest in a variety of other commercial applications. While the latter name has been applied to carrageenophyte red algae from many parts of the Southern Hemisphere as well as in the northeast Pacific, the identity of the type material and the type locality have remained unclear. The location of the type specimen of Fucus radula could not be found. We discuss available information about the probable collection location and present arguments for the collection to have been made during Cook's second voyage to southern New Zealand. Both a lectotype and epitype are designated.