Basket Fungus
Ileodictyon cibarium
Also called white basket fungus, white cage fungus, tutae whatitiri
A white latticed sphere of spongy arms that hatches from a gelatinous egg and, uniquely, detaches at maturity so the whole basket can be rolled about by wind.
Overview
The Basket Fungus is New Zealand's best-known stinkhorn and one of the most conspicuous white fungi anywhere. Its receptacle is a hollow ball built from fused, roughly cylindrical white arms enclosing large polygonal windows, so the mature fruiting body looks like a woven basket or a football-sized wire cage.
What sets Ileodictyon apart from the superficially similar Clathrus is both colour and attachment. The arms are white to cream rather than red, and are rounded rather than flattened in cross section. More strikingly, the mature lattice separates from its volva and can be blown across lawns and paddocks, a behaviour recorded in the Māori name tūtae whatitiri, thunder dung, from the belief that it appeared after thunderstorms.
It is native to New Zealand and Australia and has been reported from South Africa, Chile and other regions, often in gardens and pasture.
How to identify it
Egg
A whitish to greyish ball 3–6 cm across, half-buried, softly leathery outside, with a thick gelatinous layer over the compressed lattice and one or more white cords running into the soil.
Lattice
On expansion the receptacle forms a hollow, roughly spherical to broadly ovoid network 6–20 cm across. The arms are white to cream, spongy and chambered, more or less rounded or bluntly quadrangular in cross section, and fused into polygonal meshes 2–6 cm across. The lattice is generally not attached to the volva at maturity and often lies free on the ground.
Gleba and flesh
Dark olive-brown to blackish spore slime coats the inner surfaces of the arms, so the fresh basket looks white outside and dark within. After insects strip the slime, the arms are left bare and white. The tissue is soft, water-filled and honeycombed, and dries to a papery skeleton that may persist a while in dry weather. The volva remains as a whitish sac at the point of emergence.
Where and when it grows
The Basket Fungus fruits on rich, disturbed ground with abundant plant litter: lawns, pasture, garden beds, wood chip mulch, compost and the edges of native forest and scrub. It is common in suburban New Zealand gardens and turns up regularly in grazed paddocks.
Fruiting follows rain in mild to warm conditions, mainly from spring through autumn. Its core range covers New Zealand and Australia, with additional records from South Africa, South America and other regions where it appears to have been introduced.
Ecological role
It is saprobic, decaying leaf litter, grass thatch, wood chips and other plant remains through a network of white rhizomorphs in the topsoil and litter layer. Eggs develop where those cords reach the surface, often in loose groups.
Spores are dispersed by insects attracted to the fetid gleba on the inner arm surfaces; flies enter through the large windows of the mesh. The detachment of the mature lattice adds a secondary dispersal route, as a free basket tumbling across open ground scatters residual spores well away from the parent mycelium.
Similar species
Ileodictyon gracile is closely related but more delicate, with noticeably thinner arms, smaller meshes and a lattice that typically stays attached to the volva; it also tends to be smaller overall. Clathrus ruber is unmistakably red to orange-red with flattened arms, and remains seated on its volva.
Clathrus archeri never closes into a lattice, splaying instead into free red arms. Puffballs may resemble the unopened white egg, but sectioning a puffball reveals uniformly firm white tissue, whereas a Basket Fungus egg shows a jelly layer wrapped around the folded white lattice.