mycelial web spanning whole hillsides

Size
Height: 15–20 cm
Lifespan
1 years
Diet
Saprotrophic – fed on damp forest floors of deep podocarp-broadleaf woodlands. A hollow, net-like cage of interlaced arms, pale and ghostly, rising from the ground like a botanical skeleton. Trapped spores and insects in its web, released a smell of rotting meat, and vanished within days.
Habitat
Lowland podocarp-broadleaf woodlands of the North and South Islands. A hollow, net-like cage of interlaced arms, pale and ghostly, rising from the ground like a botanical skeleton. Trapped spores and insects in its web, released a smell of rotting meat, and vanished within days. The alien of the forest, the ghost of the leaf litter.
Range
Found in lowland podocarp-broadleaf woodlands of the North and South Islands, notably near Wellington and Nelson. Described from early naturalist accounts and preserved specimens collected in the mid-19th century. Last reliably recorded in the 1880s.
Endemism
Endemic
Main Threats
Forest clearance was the primary threat. Also threatened by the loss of deep leaf litter and changes in soil fungi communities. Last reliably recorded in the 1880s. A few preserved specimens remain in museum collections – their pale arms dried and brittle, their net-like structure collapsed, their forests turned to farms.
Population
A true giant among cage fungi, related to the living red cage fungus (Clathrus ruber) found in Europe and elsewhere. Estimated height 15–20 centimetres, significantly larger than any living Clathrus species (10–12 centimetres). Last reliably recorded in the 1880s, gone by the 1900s.
Conservation Status
Extinct
Cage fungi are the strangest of the fungal kingdom – not a mushroom with a cap and stem, but a hollow, net-like cage that rises from the ground like a botanical prison. They are the colour of pale flesh. They smell of rotting meat. They attract flies, which carry their spores to new locations. They appear without warning and collapse within days. And there was once a cage fungus that grew larger than any alive today – a net 20 centimetres tall, its arms interlaced in a complex lattice, pale and ghostly in the dark forest. It was the giant fungal net, and it is gone. Size and structure made it special. A 20-centimetre cage fungus is a spectacular thing – a hollow sphere of interlaced arms, pale and fragile, rising from the leaf litter like a ghost. Its lattice was so complex that it trapped not only flies but also small insects and drifting spores. It was a living net, a trap, a strange and beautiful thing. It attracted flies. The smell of the giant fungal net – a powerful, sickly-sweet stench of rotting meat – carried through the forest. Flies came from hundreds of metres away, drawn by the promise of carrion. They crawled over the net, searching for food. Instead, they found sticky spores, which attached to their bodies. When the flies left, they carried the spores to new locations, spreading the fungus through the forest. It also decomposed. The giant fungal net was a saprotroph – it fed on dead organic matter, breaking down leaf litter and woody debris. Its underground mycelium spread through the soil, digesting the forest floor. The net itself was the fruiting body, the reproductive structure, the brief and spectacular flower of a hidden, long-lived organism. Fungi reproduce by spores. The giant fungal net produced millions of spores on the inner surfaces of its lattice. The smell attracted flies, which carried the spores away. That strategy works when the forest is intact and the flies are abundant. It fails when the forest is cleared and the leaf litter is gone. Forest clearance and the loss of leaf litter destroyed it. When Europeans arrived, they cleared the lowland forests for timber and pasture. The giant fungal net needed deep, undisturbed leaf litter with a stable microclimate – cool, damp, dark. When the trees were felled, the leaf litter dried out. The soil warmed. The flies disappeared. Without its forest home, it could not survive. Its mycelium died. Its nets stopped rising. By the 1900s, it was gone. The last specimens were probably collected by a naturalist who had no idea he was holding the final individual. He pressed them, dried them, put them in a drawer. And the forest floor fell silent. The smaller cage fungi survived in other parts of the world. Clathrus ruber still rises from the leaf litter in Europe and North America – smaller, less spectacular, but alive. But New Zealand's giant fungal net is extinct – a ghost of the forest floor, a net that no longer traps the flies. We cleared its forest. Then we wondered why the forest floor felt so empty.