Brown mushroom

Yes, pouihi - it's called Darwinia citriodora (Seaspray) an Australian native. Here's the link for the plant http://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=2815

The centre was perhaps slightly raised but with the deeper colour and light reflection, I can't tell - anyway, I think i would have mentioned it if it had a significant umbo like those of Melanoleuca. It's a pity I did not notice it when it was younger. Still, I'd like your help anyway - even with the million others I haven't an ID for - thanks !

pouihi, Melanoleuca sp seem to have very crowded gills - the one in my spotting shows nicely spaced gills that are also adnate. Also Melanoleuca caps seems to have a slightly raised centre unlike the fairly flat cap in my photo. Thanks for checking and please let me know if you do find anything else that looks like this strangely interesting mushroom..