It digs at dawn. Not literally. The Swamp Mushroom does not move. But the mycelium spreads through the sphagnum. Slowly. Millimetres per day. The mushroom fruits in autumn. The caps are small. One to three centimetres across. Pale yellow when young. They age to ochre. The centre is darker. The margin is pale. The gills are grey at first. They darken to purple-brown. The stem is long. Thin. Five to eight centimetres. It rises above the moss. The cap opens. Spores drop. They land on wet sphagnum. They germinate. The mycelium spreads. The cycle continues. The fungus works without rest. It does not sleep. It does not pause. It grows. Habitat is permanently damp wetlands. Sphagnum bogs. Restiad peatlands. The margins of slow-moving streams. The fungus grows among sphagnum stems. It colonises the decaying lower leaves. It fruits from the moss surface. The caps sit above the water table. The stem extends downward. Reaching the peat. Reaching the mycelium. The fungus needs acidity. pH 4.0 to 5.5. It needs constant moisture. The water table must stay within ten centimetres of the surface. Drier conditions stop fruiting. The mycelium survives. It waits for rain. The rain returns. The mushrooms appear within days. The urgency is obvious. The window is short. Range across New Zealand is fragmented but wide. North Island: Northland peat bogs, Waikato wetlands, the Hauraki Plains, Rotorua lakes margins, the Moanatuatua bog near Hamilton. South Island: Westland wetlands near Hokitika, the Okarito lagoon margins, Canterbury's Ashley River wetlands, Otago's Taieri Plain, Southland's Awarua Bay wetland. Also present on Stewart Island and the Chatham Islands. The species follows sphagnum. Where sphagnum grows, the fungus may appear. Not every bog hosts it. The moisture must be right. The pH must be right. The disturbance history matters. Drained bogs do not host it. The sphagnum dies. The fungus dies with it. Diet is saprotrophic. Hypholoma elongatum decomposes the dead lower stems of sphagnum moss. Sphagnum grows from the tip. The base dies. The fungus consumes the dead tissue. It breaks down lignin and cellulose. The sphagnum collapses. It becomes peat. The process takes years. The fungus accelerates it. The mushroom fruits when decomposition is active. The mycelium spreads through the living moss. It does not harm the growing tips. The relationship is balanced. The moss grows upward. The fungus decomposes below. The peat accumulates. The carbon is stored. The fungus releases some. The bog breathes. The cycle holds. Threats are the same as threats to New Zealand's wetlands. Drainage for agriculture. Peat extraction for horticulture. Urban development filling bogs. Invasive plants like willows that lower the water table. Invasive mammals like pigs that root through sphagnum. Each drained bog loses the Swamp Mushroom. The species survives in fragments. The fragments continue to drain. The fungus retreats to the wetter centres. The centres shrink. The fungus shrinks with them. Climate change adds pressure. Drier summers lower the water table. The fruiting windows shorten. The mycelium dries. The mushroom stops. The bog dries. The fungus dies.