Inflorescences are terminal and flowers are functionally unisexual; the species are more or less dioecious.

[3] Pennantia species grow naturally in New Zealand, Norfolk Island, and eastern Australia.

In Australia, P. cunninghamii grows across a broad latitudinal natural range (nearly 3,000 km (1,900 mi)), from the south coast of New South Wales northwards through to north eastern Queensland.

[citation needed] The genus name, Pennantia, is in honor of Thomas Pennant, an 18th century Welsh zoologist and author.

[citation needed] The following four species were recognised by New Zealand botanists Rhys O. Gardner and Peter J. de Lange in 2002.