Common – but without a name

A widely distributed red alga from New Zealand receives a scientific name at last.

The most commonly occurring red alga in the algal order Bangiales in New Zealand has at last received a formal scientific name. Pyropia plicata, is an intertidal red alga, found in abundance in the North, South and Chatham Islands. It has been confused for many years with a species first collected from the New Zealand subantarctic islands in 1840. Recent research had clarified the identity and distribution of the southern species, Porphyra columbina, and also transferred it to the genus Pyropia. The description of Py. plicata was published in the open access journal PhytoKeys.

The newly described Py. plicata has a distinctive growth form with pleated blades. It has beautiful purple to grey coloration, bleaching to khaki-green on upper edges. It is found attached to high intertidal rocks by a central rhizoidal holdfast, which are hair-like extensions of the blade cells. Although the blades are only one cell layer thick they are remarkably resistant to the rigours of life on the intertidal shore and can withstand drying in the sun, and rehydrating when the tide returns.

This is one of the species that is known in New Zealand as karengo, and is highly prized by Maori as a taonga or treasure. Pyropia species are also eaten worldwide and known to be high in protein and trace elements. In Japan species of Pyropia are known as nori and are familiar to many people worldwide as the seaweed sheet that is wrapped around sushi.

"When we began work on the Bangiales of New Zealand over 20 years ago, we thought there were only a few species in this order in the southern Pacific." comments Dr. Wendy Nelson from the National Institute of Water and Atmospheric Research, New Zealand. "We have come to realise the diversity in this region is very high, and there are still many species that are undescribed. Documenting species and clarifying their relationships are important steps in understanding diversity and protecting our environment."

Nelson, W.A. (2013) Pyropia plicata sp. nov. (Bangiales, Rhodophyta): naming a common intertidal alga from New Zealand. PhytoKeys 21: 17-28., doi: 10.3897/phytokeys.21.4614

Sutherland, J.; Lindstrom, S.; Nelson, W.; Brodie, J.; Lynch, M.; Hwang, M.S.; Choi, H.G.; Miyata, M.; Kikuchi, N.; Oliveira, M. Farr, T.; Neefus, C; Mols-Mortensen, A.; Milstein, D.; Müller, K. (2011).. A new look at an ancient order: generic revision of the Bangiales. Journal of Phycology 47:1131-1151.