fruits in the damp forest leaf litter
- Size
- Cap: 10-30 mm diam.
- Lifespan
- Unknown
- Diet
- Saprotrophic, decomposing dead wood and leaf litter to release nutrients into soil.
- Habitat
- On decaying wood and leaf litter in damp native forest with high humidity.
- Range
- Found in native forests throughout New Zealand, particularly in damp, shaded areas.
- Endemism
- Native
- Main Threats
- Habitat disturbance from logging, fire, or heavy grazing affecting soil moisture.
- Population
- Common in wet forests throughout New Zealand, particularly in autumn.
- Conservation Status
- Not Threatened
- Human Risk
- caution
- Handling Note
- inedible; do not ingest
- Conservation Note
- Native fungus; not assessed by NZTCS as fungi are generally outside the scope of current threat classifications.
- Te Ao Māori
- Māori names for specific bonnet species are not recorded in standard dictionaries. In a kaitiakitanga framework, these fungi represent the hidden industry of the forest. Their role in decomposition signals the health of the ecosystem. Protecting them means preserving the integrity of the forest and the unseen processes that sustain life. The grooves are not decoration. They are structure.
Without the Oak Bonnet, the forest floor would choke on its own history. It is a decomposer, a silent worker that breaks down the dead to feed the living. The cap is small, bell-shaped, and coloured a dull grey or brownish-grey. It is dry to the touch, sometimes slightly sticky in wet weather. As it ages, the margins may fade to a paler hue, but the centre remains dark. It is a modest mushroom, easily overlooked among the leaf litter. Do not let its modesty fool you. It is essential.
The Oak Bonnet is found throughout New Zealand, from the northern forests to the southern beech lands. It fruits in autumn, often in small clusters on rotting logs or buried wood. It is not picky about its host, thriving on both native and introduced hardwoods. Its presence is a sign of a healthy, functioning ecosystem. Where it grows, decay is being processed. Nutrients are being released. The cycle continues.
The gills are white and crowded. They are attached to the stem and become greyish as the spores mature. The stem is slender, hollow, and distinctly grooved or ribbed, a feature that gives the species its name ('polygramma' meaning many lines). It does not have a ring. It does not have a web. It stands alone, supporting the small cap. The flesh is thin and fragile. It smells faintly of earth, nothing more. Unlike the Lilac Bonnet, it does not have a strong radish scent. Its defence is obscurity, not chemistry.
This fungus feeds on decaying organic matter, breaking down dead wood and leaf litter. In doing so, it releases nutrients back into the soil. It is a recycler, working in the shadows of the forest. Without it, the debris would pile up. The forest floor would stagnate. The Oak Bonnet is efficient. It consumes what is dead to feed what is living.
Threats are minimal. The species is widespread and common. However, it is sensitive to changes in moisture and soil structure. Logging, fire, or heavy grazing can disrupt the delicate mycelial networks beneath the forest floor. Recovery is slow. The fungi wait for the conditions to return. They do not rush. It carries on.