blacks out when you bruise the cap

Size
Cap: 50-100 mm diam.
Lifespan
Unknown
Diet
Mycorrhizal, forming symbiotic relationships with native trees such as beech, podocarps, and manuka to exchange nutrients.
Habitat
Under southern beech and other native trees in damp, mossy forest areas with high humidity and rich soil.
Range
Found in native forests throughout New Zealand, particularly in damp, shaded areas under beech and podocarp canopy.
Endemism
Native
Main Threats
Habitat disturbance from logging, fire, or heavy grazing affecting soil moisture and disrupting mycelial networks.
Population
Common in native forests throughout New Zealand, particularly in undisturbed damp areas with mature tree cover.
Conservation Status
Not Threatened
It looks white. It is not. The Blackening Russula begins life as a pale, creamy mushroom, convex and firm. Touch it, bruise it, or let it age, and it turns black. This is not decay. It is a chemical reaction, a defence mechanism triggered by exposure to air. The flesh oxidises, darkening from white to grey, then to a deep, ink-like black. It is a slow transformation, visible only to those who wait. The cap is broad, often reaching ten centimetres or more. It is dry, sometimes slightly sticky in wet weather. The surface is smooth, occasionally cracking with age. Underneath, the gills are white and brittle. They are spaced widely apart, attached to the stem. Break one, and it snaps cleanly, like chalk. This is a characteristic of the genus Russula. The stem is thick, sturdy, and white, though it too will blacken if handled. It does not have a ring. It does not have a web. It stands alone. This fungus forms symbiotic relationships with a variety of native trees, including beech, podocarps, and manuka. The hyphae extend into the soil, gathering water and nutrients that the tree cannot reach. In exchange, the tree provides sugars produced by photosynthesis. It is a quiet trade, essential for the health of the forest. Without these fungi, the trees would struggle. The soil would be less fertile. The forest would be poorer. Blackening Russulas are found in damp, mossy areas under forest canopy. They fruit in autumn, often singly or in small clusters. They are edible, though their quality is debated. Some find them bland, others appreciate their firm texture. They must be cooked thoroughly. Raw, they can cause gastrointestinal distress. They are best collected when young and white, before the blackening begins. 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.