Gunnera hamiltonii is a creeping herbaceous plant in the family Gunneraceae, with clusters of small (2 to 7 cm) grey-brown leaves forming a dense mat. Small green flowers are followed by red berries in the autumn. It is one of the rarest plants in its native New Zealand, with Southland and Stewart Island/Rakiura representing two of the suspected 5 remaining natural habitats. Natural fertilisation of these plants is now difficult as the male and female plants are separate.