The darker side – Dark Honey Fungus

Following on from my previous post covering the Honey Fungus, I felt the need to feature this common and equally destructive Armillaria species. Again, it’s cap is variable and looks very similar to the standard Honey Fungus, but with a few distinctive visible differences.

The Dark Honey Fungus (Armillaria ostoyae), like A.mellea, often grows in large, clustered groups on or around deciduous and coniferous tree stumps, logs or even shrubs. It can fruit early, in the summer months and continue to do so up until early winter. Sometimes it appears as if growing on soil or grass, but they are actually fruiting from dead roots underneath the soil.

At first glance, the Dark Honey Fungus looks pretty much the same as the Honey Fungus as it has similar cap colouring, ranging from yellow-brown to dark brown, although they are more often darker brown. As mentioned, shapes are a little variable, with some rounded and others wavy and/or with a central depression or shield shaped. This is dependent on age also. Caps can also grow slightly larger; up to 15cm across.

The scales (or fibrous flecks) on the cap surface are much more prolific at the centre, and are a much darker brown. A decisive key difference when compared to the A.mellea can be seen on the bottom/edge of the ring, high up on the stem. If you look closely, there are dark brown markings at the edge whereas they would be pale yellow on A.mellea. So take a close look as this will aid in identification.

Safe to eat?

Most consider this fungus edible but must be cooked well and only a little tried first as it can cause stomach upset for some people. Because of this, some experts believe it to be poisonous and not worth trying.

Strange but true!

And just before I sign off, here’s an interesting titbit for you; A new record holder for the title of the world’s largest known organism was recently discovered in 1998. It was actually a Dark Honey Fungus (Armillaria ostoyae) covering approximately 2,384 acres of soil in Oregon’s Blue Mountains, USA. Based on its current growth rate, the fungus is estimated to be 2,400 years old but could be as ancient as 8,650 years, which would earn it a place among the oldest living organisms as well. Read more here: www.bbc.co.uk/earth/story/20141114-the-biggest-organism-in-the-world

Dark Honey Fungus – Armillaria ostoyae. Notice the dark brown flecks covering the cap (densely packed at the centre) and the dark markings on the edge of the whitish ring.