Mānuka and kānuka are two of the most common plants in New Zealand. They are often linked as one species, pronounced locally as mar-new-ka, but in fact are in different genera (Leptospermum and Kunzea, respectively) and usually grow in different habitats.
They are similar in being able to regenerate through grassland on lightly grazed hillsides and hence have the reputation as weeds. Ecologically, however, they are important early stages in forest regeneration and are very important bird, lizard and insect habitats as well. But because they are aromatic they both burn very easily.
Mānuka grows in wet or infertile places, often around estuaries and other wetlands like the Anchorage wetland. The masses of flowers produce a large amount of nectar, and mānuka honey has become famous for its aromatic medicinal qualities.
One of the reasons why mānuka is such an effective coloniser is the vast number of nutlike capsules it produces that open in hot dry conditions (such as when fire is present) to release an enormous number of tiny seeds that scatter widely in the wind.
Kānuka grows in more fertile drier places and can cover large expanses of hillside. Initially tall and dense it starts to breakdown with age and enable shrubs, tree ferns and forest trees to establish. Along the track you will see kānuka forest with a tree fern understory and places where rimu is regenerating.
Both species were very important to Māori for building materials (long tough stakes and poles), weapons and tools from the hard wood, and medicines from the leaves. Early Europeans made tea and called these plants “tea-tree”.