Abstract
Iti lacustris, a small annual herb from Fiordland, south-west New Zealand, is described and illustrated. It belongs in tribe Sisymbrieae, but its adaptations to an unusual habitat and its unspecialised reproductive morphology obscure its affinities.
Iti lacustris is a minor component of lake-edge turf on cobble beaches at Lakes Manapouri and Te Anau. Although I. lacustris is rare and possibly endangered, its distribution within Fiordland National Park, and the legal confinement of the levels of Lakes Manapouri and Te Anau, provide considerable protection of its habitat.