Fungi Key – Ganoderma

This is a trial key for Queensland Ganoderma. QMS would greatly appreciate your feedback: info [at] qldfungi.org.au

Background

The taxonomy of the genus Ganoderma has been described as chaotic. Worldwide there are over 200 described taxa, but, due to the extreme plasticity of morphological characters in this genus, very few reliable descriptions exist which facilitate accurate recording of these fungi in the field. The only readily available reference to the genus in Queensland is Hood’s (2003) “Introduction to Fungi on Wood” which lists 11 species, only three of which are acknowledged as being present in Queensland according to more recent molecular research. A comprehensive publication by Ryvarden & Moncalvo (1997) was published by Fungiflora in Oslo but it is not easily accessible. More recently, papers by Smith and Sivasithamparam (2000; 2003) examined Australian taxa in considerable detail and concluded that only 6 species were present, and 5 of these were found in Queensland. Neither of these publications, however, provide a reliable means of identification of Queensland Ganoderma to species level.
 

Ganodermas in Queensland

We see Ganoderma sporocarps on almost every QMS foray and frequently have rather inconclusive discussions about their identity. As Smith and Sivasithamparam point out, the morphological differences between Ganoderma species are small and indistinct and neither pore density nor spore size provide reliable ways of separating species. It is therefore not surprising that they did not include a key in their 2003 paper. Some of their results are summarised in Table 1 below.

Table 1. Ganoderma species in Australia

Species	Surface	Pores/mm	Spore sizes	Records in Queensland
G. australe	Matt	3.0-4.5	9.1-11.8 × 5.5-9.1	25
G. incrassatum	Matt	3.6-5.9	6.8-10 × 5-6-8	1
G. steyaertanum	Laccate	3.4-5.6	7.3-12.7 × 5-9.5	13
G. chalceum	Laccate	3.4-5.6	8.2-11.8 × 5.5-10	8
G. boninense	Laccate	3.2-5.0	8.2-13.5 × 5-8.6	0
G. weberianum	Laccate	2.7-5.9	6-10.9 × 4.5-7.3	2

 
Host and habitat details seem to be particularly lacking in the published literature. Differences in distribution, fruiting body texture and spore morphology may nevertheless provide just enough information to allow the production of a trial key. Indeed, the aim of this article is to provide a trial key for Ganoderma in Queensland, as well as notes on species – as a tool for improving our recording practices.
 

Key

1.	Fruiting body matt (dull)	2.
1.*	Fruiting body laccate (polished like furniture)	3.
2.	Fruiting body sessile (no stem), 50 – 500 mm diameter, with a white or pale margin and spores distinctly truncate.	Ganoderma australe
2.*	Fruiting body stipitate, spathulate or occasionally sessile, < 40 mm diameter, margin concolourous and spores indistinctly truncate.	Ganoderma incrassatum
3.	Spores Q > 1.7 on average	Ganoderma boninense
3.*	Spores Q < 1.6 on average	4.
4.	Fruiting body large, 50 – 500 mm diameter, red-brown or black, in rainforests or vine forests, usually near the ground.	Ganoderma steyaertanum
4.*	Fruiting body small to medium, 30 – 90 mm diameter, in sclerophyll forests.	5.
5.	Spores truncate, smooth, 8.2-13.5 × 5 – 8.6 µm	Ganoderma chalceum
5.*	Spores ovate, finely echinulate, 6-10.9 × 4.5 – 7.3 µm	Ganoderma weberianum

 
Notes:
Truncate means cut off at one end.
Q is the length of the spore divided by its width.
Echinulate means spiny.
 

Species Descriptions

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Ganoderma australe

This is the most frequently seen matt species in South-east Queensland. It forms large, 50 to 500 mm diameter, shelf like brackets growing on Eucalyptus and other hardwood trees in wet and dry sclerophyl forests. The surface often uneven and shows growth bands and is a pale matt brown. The margin is often paler or even white. The flesh is brown and very hard and wood like. The lower surface is poroid, white or ochraceous in living specimens and stains dark brown when scratched. There are usually 3 – 4.5 pores per millimetre.

The spores are produced in very large quantities and can often be seen coating both the surface of the bracket and the surrounding area, they are pale brown. They are ovoid-ellipsoid with an ornamentation of small dark warts, a thick septate wall and a clearly truncated end.

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Ganoderma boninense

Basidiocarp stipitate, substipitate or sessile, kidney shaped. Typically 30 – 90 mm across. Surface in concentric zones, violet brown to black, laccate shiny, with a paler margin. Flesh greyish to brownish orange. Pores pale yellow, 3 – 6 per mm. The distinguishing feature appears to be its elongated ellipsoid spores with a Q-value (Length /width) of 1.7 or greater.

This laccate species has not so far been reliably recorded in Queensland. It has, however, been found in New South Wales.

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Ganoderma chalceum

Basidiocarp stipitate, substipitate or sessile, kidney shaped. Typically 30 – 90 mm across. Fruiting body highly laccate when fresh, from bright red brown to almost black, with concentric zones which can be in contrasting colours. Margin pale. Flesh hard, pale reddish brown. Pores very pale yellow, 3.5 – 5.5 per mm. Spores brown, thick walled with septa in the wall, more or less smooth, truncate, 8.2-13.5 × 5 – 8.6 µm.

Small to medium laccate species which are distinctly stipitate and have smooth truncate spores are most likely to be G. chalceum.

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Ganoderma incrassatum

There are several records, but only one collection of this species. It appears to have a northerly distribution and to favour rainforest habitats. The fruiting bodies are small, up to about 40 mm diameter and generally stipitate or spathulate. They are dark brown to almost black in colour and matt. The surface is wrinkled and shows concentric zoning. The margin is concolourous as the crust overhangs the pores. The flesh is dark brown, hard and quite thin, 2 – 3 mm. The pores are yellowish brown and there are 3.5 – 6 per mm.

It is readily distinguished from G. australe where the specimens are small and stipitate or spathulate. Where specimens are sessile, examination of the spores is a good guide with this species having warty spores with a thick septate wall, but unlike G. australe they are ellipsoid and indistinctly truncate.

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Ganoderma steyaertanum

This laccate species can be readily distinguished in its large, 50 -500 mm diameter, fruit body. The attachment is sessile or can be broadly stipitate. The fruiting body surface is uneven, with concentric zones and dark brown (Chestnut) to almost black fruiting body. Margin yellowish white. The pores are pale yellow to greyish orange and there are 3.5 – 5.5 per mm. The spores are brown, ovoid ellipsoid with an average Q below 1.6. They are echinulate, thick walled and and usually truncate. This species appears to favour rainforest habitats.

Specimens that are red brown and stipitate can occur and are more difficult distinguish from G. boninense, G. chalceum and G. weberianum.

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Ganoderma weberianum

Basidiocarp laccate and stipitate or spathulate up to 50 mm wide. Violet brown to dark brown to black. Radially and concentrically wrinkled, with a pale yellowish margin. Stipe short, 10 – 15 mm and dorsally attached. Flesh greyish orange, hard. Pores pale yellow, 3 – 6 per mm. Spores ovoid, thick walled, echinulate, 6 – 10.9 × 4.5 – 7.3µm.

Small to medium laccate species which are distinctly stipitate and have finely echinulate and smaller spores are most likely to be G. weberianum. This is the species illustrated in Fuhrer under the name of Ganoderma resinaceum.

Note: The QMS does not have a reliable photograph of this species and it would be greatly appreciated if members could look out for the species, and supply a photograph having checked the spores.

Pat Leonard
August 2012