Kingdom:   Fungi
Division:    Basidiomycota
Class:        Agaricomycetes
Order:       Agaricales
Family:      Physalacriaceae
Genus:      Armillaria
Species:     A. hinnulea
Binomial name: Armillaria hinnulea

Armillaria hinnulea is a species of mushroom found only in Australia and New Zealand. It is a secondary pathogen (i.e., causing disease only after a primary pathogen has damaged the host) of wet native forests.  It appears first as an immature mushroom with a rounded blackish rough cap and a thick white stalk.  The stalk is covered with white fibres and is bulbous at the base. A fine cortina (cobweb-like partial veil) extends from the cap margins to the stipe.
Mature specimens of Armillaria hinnulea have flattened brown to olive-green caps with a dark granular material on the centres.  Gills and stripes are a pale cream.

Immature mushroom.
Genus Armillaria-001.JPG

Armillaria hinnulea.JPG

Genus Armillaria-002.JPG

A mature mushroom.
800px-Armillaria Fungi 5969.jpg

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/