Places with bare acidic soil, scattered lichens and mosses and scattered trees of kānuka and mānuka are ideal habitats for ground orchids.
New Zealand has nearly a hundred species of orchids. Nearly all of them have tubers under the ground, fleshy roots associated with fungi that help the orchid absorb nutrients, and in spring one or a few new leaves emerge, and then in summer a flower-bearing shoot grows up. The leaves are usually grass-like and soft and fleshy. The flowers are intricately shaped and coloured.
One species, usually growing in shaded parts of the track, is called ‘greenhood’ owing to the colour and shape of the flowers. The often strange flowers of orchids make them favourite and challenging subjects for photographers. Some orchids are very common and widespread, others rare and local.
Both types occur in the park, where the soil is derived from granite. Most of the orchids along the track are sun-orchids in the genus Thelymitre, named because the flowers open only in the sun. The tubers under the ground are edible and the Māori name of many orchids includes ‘ika’ (such as māikaika) referring to the clusters of tubers.