This is a corticioid genus, meaning that the fruitbodies are fairly flat. Typically, they grow on the underside of wood that’s lying on the ground. The fruitbodies are often some shade of brown (e.g. pale greyish brown, brownish-yellow, orange-brown, very dark brown). The fruitbody texture ranges from something resembling compressed fairy floss to more compact (sort of mousse-like to somewhat felty). Usually there is at least a slight furriness or fuzziness to the surface.
They were once thought to be decomposers but research has shown that many species are mycorrhizal. The mycelia are active in the soil and simply need some above ground objects to support the fruitbodies. Dead wood lying on the ground is the most common and most robust support to be found in a forest or woodland. However, fruitbodies have also been found on soil banks or on the lower surfaces of stones or rocks
The genus is found worldwide in a great variety of habitats.
Look-alikes
If you see a brown, non-cobwebby, markedly furry/fuzzy carpet-like growth on the underside of dead wood that is lying on the ground – it is very likely you have a species of Tomentella. The genus is fairly common in our area.
Coniophora fruitbodies are often brown but generally are not markedly furry/fuzzy or they have extensive white(ish) thread-like to cobwebby margins (as shown here:https://www.anbg.gov.au/fungi/images-captions/coniophora-olivacea-0182.html), not a feature of Tomentella.
Septobasidium fruitbodies are often brown and felty – but are on live plants (since the fungi parasitize scale insects) and may be found on all sides of a branch – not just the underside.
Some Haplotrichum fruitbodies are brown and fuzzy – but are very flimsy.
Some species of Tomentella are more greyish and then naked-eye identification becomes difficult since there are various corticioid genera with greyish fruitbodies.
In the northern hemisphere there are some macroscopically similar brown species of Pseudotomentella, but such species are not known from Australia.
Tomentella sp. is listed in the following regions:
Canberra & Southern Tablelands