Identifying Southern Bracket (Ganoderma australe)

Take great care when identifying wild plants and fungi, this blog is not a resource to be taken by itself and further resources will be linked. Consult other sources and double check. While foraging is an extremely rewarding and useful skill, numerous common plants and fungi can make you sick or kill you. Be absolutely sure of what you’re eating and, when gathering, ensure you leave enough not only to ensure the survival and growth of the species but also enough for others to enjoy, from the human and more-than-human communities. Also cultivate an awareness of contamination and pollution – wastewater runoff, spraying, exhaust fumes – as this should affect your decision to harvest.

The Mushroom

Ganoderma australe is a type of polypore an bracket fungi in the genus Ganoderma and is part of the Polyporaceae family. They are a parasitic mushroom until the tree they are growing on dies and then they become saprophytic. They are commonly found in the tropics but are also spread throughout Britain, Australia, and New Zealand. The genus name Ganoderma comes from the Greek word Ganos (shining/bright) and derma (skin), meaning “shining skin”, though not all Ganoderma species have shiny surfaces including this one. Australe simply means “Southern”.

Description:

This species lacks a stipe and grows very large, directly from the tree trunk. The young fruiting bodies appear as white balls and grow into large flat brackets, typically 25cm across (though up to 50cm) and 5-25cm thick. They have a lumpy dark brown or reddish upper surface (greenish if algal stained) with a distinct white under layer with a clear margin between the top and the underside. You can see many small pores on the white underside and if you touch or scratch the underside it will turn brown. As with other Ganoderma species they produce many reddish-brown powdery spores which can settle on other bracket fungi nearby, on the tree, and on the fungi itself. Throughout their whole life cycle southern bracket is extremely tough, and woody. Each year they will grow a new layer from the underside which will eventually turn brown and so you can often see many layer and potentially count how old the mushroom is.

Ecology

Ganoderma australe can be found growing on live and dead trees, primarily on the lower part of a trees trunk. They largely grow on beech, oak, sycamore, lime, and birch and cause very serious white heart rot which will eventually kill the tree. Southern bracket is a perennial and can be found all year round, often growing in tiers on the same tree.

Nutritional & Medicinal Information

The mycelia of Ganoderma australe has been showed to increase high density lipoproteins and lower cholesterol, potentially helping those at risk of heart disease and high cholesterol.

The mycelium of the Ganoderma species are said to boost the immune system, regulate the metabolism, and also inhibit tumour growth.

Possible Lookalikes

Artist’s Bracket (Ganoderma applanatum) looks very similar to southern bracket. The Yellow Flat-footed platypezid fly (Agathomyia wankowiczii) only uses Artist’s bracket to lay their eggs and so the underside of this bracket fungi can often be found covered in clusters of galls (each housing one grub of this fly). They are also less common than southern bracket and generally has a thinner outer crust and margin. Ganoderma applanatum is also medicinal however.

Interesting Facts

When the host tree eventually dies and falls over from heart rot southern bracket can grow a new shelf from their old one in order to correct their orientation and so they can continue dispersing spores effectively.

Storing & Cooking

Unfortunately southern bracket is not generally considered edible as they are far too hard and woody (though they are not poisonous). In some Asian cuisines, however, they use Ganoderma species cooked and/or soaked in acids such as lemon juice to soften the mushroom and use as an umami flavour enhancer in fermented foods.

Further Reading

iNaturalist

First Nature

Nature Spot

New Forest National Park

TMA

Queensland Mycological Society