Armillaria ostoyae - Dark Honey Fungus

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Agaricales

There are many forms of Honey Fungus, and in some books they are all given the scientific name Armillaria mellea even though it is now accepted that there are several distinct species.

This parasitic fungus can do immense damage to forests; it attacks both coniferous and broad-leaf trees. By the time the fruit bodies are in evidence, the damage internally is usually so great that the tree is doomed.

Identification Guide

Cap	5 to 15cm in diameter, deeply convex then flattening with a depressed centre; colour typically red-brown but hygrophanous and drying out much paler; covered in brown scales when young, but these are less evident at maturity, when the margin becomes virtually scaleless but noticeably striate. The cap flesh is white and firm.
	Gills The weakly decurrent gills are crowded andwhite, gradually becoming cream or pibkish buff. Stem White above the ring; coloured as cap below; cylindrical; 5 to 15mm in diameter and 6 to 15cm tall with a finely woolly surface. The stem flesh is white, full and fairly firm. A whitish double ring with distinctive dark brown or black scales on its underside persists to maturity.
Spore print	White.
Odour/taste	Faint acidic odour and taste strongly acidic. (Considered edible if well cooked, but some people find this mushroom indigestible.)
Habitat	Parasitic on or up against broad-leaf and conifer trees; also occurring on stumps and roots, and occasionally on fallen branches.
Season	July to November.
Occurrence	Very common in most areas where the soil is acidic.
Similar species	Armillaria mellea, Honey Fungus, has a very scaly cap and a yellowish stem ring without dark scales on its underside. Armillaria tabescens, sometimes referred to as the Ringless Honey Fungus, has no stem ring and its gills turn pinkish-brown at maturity. Armillaria gallica has a bulbous stem and a fleeting cobweb-like ring that becomes merely a yellowish ring zone at maturity. Pholiota squarrosa is generally similar in colour and covered in scales; it retains an in-rolled margin, its gills turn uniformly rusty-brown, and it has a radish-like smell and taste.