Ileodictyon gracile (Smooth Cage) is a stinkhorn fungus. There is nothing horn-like in the appearance of this fascinating fungus, rather, it resembles a lattice structure, and is therefore sometimes referred to as Lattice or Basket Stinkhorn Fungus.
With a gentle nudge with the boot, this fungus sprung from its outer skin with the speed and surprise of a Jack-in-the-box - it was an exciting spectacle. I nudged others, but they obviously were not mature, and did not spring open.
An intact Illeodictyon gracile (Smooth Cage)
is made up of polygons resembling a hollow soccer ball
I have had a marvellous time observing these fungi in my garden following recent rain. As soon as I discovered the 'eggs' amongst fallen autumn leaves on my lawn, and felt their rubbery texture, I realised they were a stinkhorn fungus of some sort.
Habitat of Ileodictyon gracile includes mulch and woodchips, on the ground and leaf litter in gardens or on edges of tracks, and in native forests in southern Australia. It grows singly or in groups, and according to Fungimap Australia, is common and widespread.
An 'egg' (unopened sac) of Ileodictyon gracile
- off-white in colour and up to 40mm diameter
A dissected young 'egg' of Ileodictyon gracile
The flat arms broaden out where they join, distinguishing this fungus from the similar Ileodictyon cibarium (Crinkled Cage). The fruit body can apparently be up to 300mm in diameter, with up to 30 meshes formed by a spherical network of linked arms. The cage can become free from the remains of the casing and roll freely along the ground. The width of the arms is up to 5mm.
I unintentionally ran over this stinkhorn egg with
the mower, exposing the folded 'arms'
The spore mass (gleba) is brown and slimy, and forms on the inside of the arms. It smells sour, but not fetid like some other stinkhorn species.
Notice the widening of the arms where they join (an identifying feature). Also notice the remains of the outer skin ('egg') of the fungus on the right. This stinkhorn has been damaged by slugs and rain.
Ileodictyon gracile is reported to be native to Australia, New Zealand, and Chile, and has been introduced in East Africa and Europe.
My sightings of Ileodictyon gracile
[This will be updated with fresh observations]
Singleton (Hunter Valley, NSW) - Urban, on ground under deciduous tree - Jun 2009, Jul 2010, Jul 2011
Jesmond (Hunter Valley, NSW) - Parkland, on woodchipped garden - Jun 2009
Below is a series of photos showing interesting characteristics. An egg of Ileodictyon gracile in my lawn has been invaded by slugs - note, in this image, the slug has its head buried in the fungus . . . . .
. . . . . as slugs have been feeding on this fungus for a week, I presumed the stinkhorn would not reach maturity intact, so I picked it to examine it - note the conical shape . . . . .
. . . . . I carefully peeled the outer skin from the fungus, leaving a solid structure with the feel and consistency of hardened gelatine. When I pulled the outer pieces from the stinkhorn, the imprint of the lattice arms was left (the dark speckles are dirt) . . . . .
. . . . . the Smooth Cage was compacted like tough rubber, and could not be separated without breakage - I presume that as air had reached the fungus via the hole the slugs were feeding through, the fungus has hardened. Note, the brown substance adhered to the inside of the arms is the gleba (spore mass), which had also hardened.