Foliose species of New Zealand red algae: diversity in the genus Tsengia (Tsengiaceae, Halymeniales), including T. northlandica sp. nov.

ABSTRACT

Identification of foliose red algae is particularly problematic as many of the characters used, such as general overall habit, colour, and texture, are often dependent on environmental or developmental characteristics of the specimen in question. One foliose red algal genus that has received little attention and is quite common in parts of New Zealand is Tsengia. Collections of multiple foliose specimens of Tsengia from various locations and habitats in New Zealand have highlighted the wide morphological variation that exists within single species. Our molecular data clearly show three foliose species of Tsengia, two of which are associated with previous names (T. laingii, Nemastoma laciniatum) common in southern New Zealand, and one species described from this study, T. northlandica sp. nov., from northern New Zealand. The discovery of another foliose species of Tsengia in Stewart Island suggests greater diversity in this group that will only increase the difficulty in determining species from field collections. While these foliose species are distinct using various molecular species delimitation techniques, morphologically they are extremely diverse (plastic) with overlapping habits.

KEYWORDS:

• Bay of Islands
• Foliose
• LSU
• Macroalgae
• Nemastoma
• Phylogeny
• rbcL
• Rhodophyta
• Species delimitation
• Stewart Island
• Taxonomy

ACKNOWLEDGEMENTS

We thank Antony Kusabs (WELT) for assistance with herbarium specimens, and Chris Hepburn (University of Otago) for field assistance. Debbie Freeman and Don Neale (Department of Conservation) are thanked for collecting at the subantarctic islands. Judy Sutherland is thanked for the sequence of Tsengia feredayae. Images of the type specimens (T. laingii and T. laciniata) are courtesy of Lund herbarium, photographed by Wendy Nelson.

SUPPLEMENTARY MATERIALS

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Additional information

Funding

This work was supported by the Strategic Science Investment Fund (SSIF) and the National Institute of Water and Atmospheric Research (NIWA).