Kingdom: Fungi
Division: Ascomycota
Class: Lecanoromycetes
Order: Peltigerales
Family: Lobariaceae
Genus: Sticta
Species: S. filix
Scientific name: Sticta filix

Sticta filix is a lichen that has green phycobiont (algae). The green thallus stiffly projects out from the substrate on a short basal stalk. On the thallus underside continuing up from the stalk is a very dark brown rib-like structure. The dark brown colour shades to a light brown towards the margins of the much-dissected thallus. This is a distinguishing feature of S. filix.
Also on the undersurface are small pale pits called true cyphellae (a pore recessed into the lower thallus surface).
Due to its green phycobiont, it can thrive in deep shade.

Sticta filix was New Zealand's first lichen to be described and illustrated by Menzies, Johann and Georg Forster during Cook's second voyage 1772-1775. Samples are still preserved in the British Museum.

Sticta filix.JPG 

The underside of the thallus.
Lichen Sticta filix-003.JPG

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/