"Pakau is a monotypic genus erected by Fawcett & Smith (2021) to accommodate Pneumatopteris pennigera. Pakau differs from Pneumatopteris by having exindusiate sori, by the presence of costal scales, and by the absence of rudimentary proximal pinnae."

https://www.nzpcn.org.nz/flora/species/pakau-pennigera/