Unnamed for over 30 years: Gigartina falshawiae sp. nov. (Gigartinaceae, Rhodophyta) and its confusion with Iridaea tuberculosa in New Zealand

A newly described red algal species, Gigartina falshawiae, has been identified from Stewart Island, New Zealand, resolving a long-standing taxonomic confusion with Iridaea tuberculosa. The discovery clarifies that G. falshawiae, previously mislabeled as I. tuberculosa in Lindauer's collection, is distinct in morphology—featuring forked, bushy thalli with marginal proliferations and lobed cystocarps—while I. tuberculosa exhibits fan-shaped thalli without proliferations and globose cystocarps. Additionally, their distributional ranges differ: G. falshawiae is endemic to Stewart Island, whereas I. tuberculosa occurs on the New Zealand subantarctic islands (Antipodes, Auckland, and Campbell Islands), with both species co-occurring on the Snares Islands. This study corrects a 30-year-old misidentification, enhancing our understanding of Gigartina taxonomy in New Zealand.

D’Archino, R., Nelson, W. A., & Sutherland, J. E. (2019). Unnamed for over 30 years: Gigartina falshawiae sp. nov. (Gigartinaceae, Rhodophyta) and its confusion with Iridaea tuberculosa in New Zealand. Phycologia, 59(1), 45–53. https://doi.org/10.1080/00318884.2019.1667187