the coprosma with the worst smell in NZ's bush
- Size
- Height: 3–5 m, Spread: 2–3 m
- Lifespan
- 50–80 years
- Diet
- Not applicable (shrub/small tree). Photosynthetic.
- Habitat
- Forest understorey and scrub, often in damp, shaded sites. Prefers fertile, well-drained soils with partial shade. Often found in mature forest and along stream banks.
- Range
- North Island and northern South Island from Coromandel southwards. Most common in lowland and montane forests. Absent from much of the eastern South Island.
- Endemism
- Endemic
- Main Threats
- Habitat loss from land clearance is the primary threat. Browsing by introduced possums and deer. No significant pest or disease issues. Protection of lowland forest is critical.
- Population
- Populations are considered stable in remaining forest fragments. The species is common in forest understorey throughout its range. It is threatened by ongoing habitat loss and browsing by possums.
- Conservation Status
- Not Threatened
Most easily recognised by the rotten-egg smell released when its leaves are crushed. A plant that announces itself through stench.
The leaves are a dull light green and oblong or egg-shaped, up to 10 centimetres long. The small, insignificant flowers are followed by small berries that are pale blue or white when ripe. The unpleasant smell deters browsing animals, allowing the plant to thrive in forests where other species are heavily browsed. A plant that survives by smelling terrible.
The leaves contain chemicals that produce the characteristic odour. The smell has been compared to rotten eggs, sewage, or boiled cabbage. It is strongest when the leaves are crushed or damaged, but it can also be detected on warm days when the plant is undisturbed. The odour is thought to be a defence mechanism, deterring browsing by possums and deer. A plant that fights back with chemistry.
The stems are slender and branching, with pale grey bark. The plant grows as a shrub or small tree, often in the shade of larger trees. It is slow-growing and long-lived, with some individuals estimated to be over a century old. A plant that takes its time.
The berries are eaten by birds, which disperse the seeds. The fruit is not palatable to humans, but it is an important food source for native birds in the forest understorey. A plant that feeds the birds, even if it repels the people.
The Māori name Hūpiro means stinking or foul-smelling, a direct reference to the plant's most notable feature. Despite its unpleasant smell, the plant has value in the forest ecosystem, providing food for birds and shelter for insects.
The forest is quiet. The stinkwood stands in the shade, leaves dull green, berries pale blue. A possum approaches, sniffs, and turns away. The stinkwood does not move. It does not need to.
Its smell is its shield. And the shield works.