An Arrhenia acerosa fruit body consists of a cap that is fan-shaped or semi-circular, possibly lobed or somewhat uneven in outline and up to 3 cm or so in diameter. The cap is either stemless or with a rudimentary lateral stem and there are gills on the underside of the cap. The cap is whitish, grey or grey-brown and the colour may vary depending on whether the cap is moist or dry.
It grows amongst or near mosses or on litter close to the soil or mosses.
Arrhenia acerosa is the name given to the subject of a photo on page 34 of G. Gates & D. Ratkowsky book: A Field Guide to Tasmanian Fungi, Tasmanian Field Naturalists Club, 2016 (2nd. ed.).
The species is widespread in the northern hemisphere and descriptions generally note the cap as smooth or centrally pubescent. However, some sources note the caps as having radial fibrils and show pictures of slightly hairy caps. I have created 'hairy acerosa' on Canberra Nature Map to accommodate a sighting by RyuCallaway at Burrinjuck that (while not identifiable) is far too intriguing to be discarded. I have made two assumptions: (1) there are gills on the undersides of the caps and (2) the caps are growing from soil, not from buried wood. There are few genera of fungi that produce stemless caps directly from soil and, combined with the grey colour and mossy habitat, Arrhenia seems a likely genus and within that genus, acerosa seems to be a superficially similar species.
Receive email alerts when new sightings are reported.
Arrhenia 'hairy acerosa' has been recorded at: