Pholiotina rugosa

The fruitbody is a mushroom with a cap atop a central stem. The smooth to slightly wrinkled cap may be up to 3 centimetres in diameter and is conical to convex but flattens with age and then may have a central hump (or umbo). The cap is in shades of yellow-brown, orange brown or reddish-brown and with a striate margin when fresh. The gills are pale yellow brown to rusty-brown. The creamy to brown stem may grow to 5 or more centimetres long and a few millimetres wide.

A partial veil is present in the young mushroom. Once the cap has expanded you see the veil remnant as a pronounced horizontal collar around the stem, though with time this may disappear. There is no universal veil.

Hausknecht says it is probably worldwide in distribution, in habitats from suburban gardens (e.g. on soil or woodchips) to forests.

Toxicity: Northern hemisphere studies have found amatoxins in this species. Those are the deadly compounds found in Amanita phalloides (the Deathcap).  

Synonyms: You may find Conocybe filaris, Pholiotina filaris or Conocybe rugosa used for this species (even in fairly recent publications) or a difference of opinion (e.g. Knudsen & Vesterholt keep Pholiotina filaris distinct from Pholiotina rugosa).

Look-alikes: Hausknecht notes a few macroscopically similar European species of Pholiotina. If the same were true in Australia then visual sightings would need to be labelled 'Pholiotina rugosa group'. Galerinas are common in similar habitats, though most Galerina species are more delicate or with flimsier veil remnants. When a more solid veil is present the remnant ring generally does not not stick out as a horizontal collar. Species of Descolea have similar pronounced collars and (depending on species) differ in various ways from the description given above.

References

Hausknecht, A. (2009). A monograph of the genera Conocybe Fayod, Pholiotina Fayod in Europe, Edizioni Candusso, Alassio.

Knudsen, H. & Vesterholt, J. (eds). (2018). Funga Nordica, Nordsvamp, Copenhagen.