This morning upon finishing the usual morning walk with our dog Sammy at our front gate, Sammy decided he would like to take a wander further south towards our neighbours. Well, I'm very glad I decided to indulge him. Not far into the bush, I realise Sammy is tracing my steps through the bush on my usual journey through the property and that yet again, he's led me to one of my favourite species, Amanita umbrinella, The Australian Umber Amanita!
One of the reasons I was very excited to find another observation of this species in recent weeks, was that the last two times I'd observed this species over the last week or so, they were subsequently devoured/disturbed by something upon returning to the sites to photograph them - such a photography downer!
Of the first observation this year, I could not be sure was animals, as it was alongside a dirt road and accessible by those passing by, and for that reason, I could not rule out human intervention - particularly as this species can be mistaken for Amanita rubescens "The Blusher", which is an apparently 'edible' species Wild Food Huntress (2021). (Hoping not as we do not know the safety of this Australian species!)
Anyway, after the initial disappointment of the disturbed mess of these Amanitas along the roadside, I decided to go south where it may be a little bit more damp, exploring further back towards our house and opposite the front gate. For some reason, I got a 'vibe' to go check out this small patch of area, still within Nothofagus forest, but approx. 1-2 metres away from the dirt/gravel private road.
Low and behold, I see another observation of Amanita umbrinella!! BAD NEWS however!: Again, only remnants of this species observable upon the leaf litter, looking like something or someone, had disturbed the mushrooms. The GOOD news was that this time, I knew because of the remote and private location, that human disturbance was most unlikely, therefore, I knew at least, that it appeared as though some kind of fauna were feeding on it - which made me quite happy!
However, this said, it was still no indication of exactly WHAT was eating these Amanitas - a riddle that would be solved today!
All was revealed this afternoon, when, upon my return to the fresh observation, and with heavy camera equipment in tow, eager to take some photos, I observe a quite robust Pademelon (wallaby), at the site of the fruiting bodies.
CAUGHT IN THE ACT!
As I came upon it, it ran away startled, and further tracing its steps where it had run away, I see partially disgarded cap remnants further past the original disturbed fruitbodies. This seems to indicate to me that the Pademelons had been eating these Amanitas and as it dispersed, it dropped parts of the cap it had been feeding on. It appears to be clear after witnessing this incident that Pademelons indeed eat this species.
Learnings on Amanita umbrinella - The Australian Umber Amanita
First described by E.J. Gilbert and Cleland in1941 and has a number of synomyns including Amanita bambra - described by Grgurinovic, 1997 in her book the Larger Fungi of South Australia p. 389, fig. 259(a-d). The description of A. bambra is apparently based on the same notes on fresh material on which A. umbrinella was based (Tulloss 2021).
The name Amanita umbrinella - The Australian Umber Amanita
umbrinus "umber" - colour of the cap and ella - diminutive ending; "little umber thing" (Tulloss 2021)
The name bambra is an aboriginal name which means "mushroom" (Grgurinovic 1997)
Amanita umbrinella - Identification
Amanita umbrinella - Identification
Out of the around 111 endemic Amanita species, (found only in Australia) (Tulloss 2009), Amanita umbrinella is part of the 'southern temperate clade' - known formally as the Amarrendia clade, that includes Amanita species from South America, New Zealand and Australia (Justo et al. 2010).
Amanita umbrinella has been observed according to the Atlas of Living Australia and iNaturalist as an endemic species only occurring in Australia, however I notice some records on the GBIF—the Global Biodiversity Information Facility, within Australia and Argentina. Are these Argentinian records just misidentifications of Amanita morenoi - which looks similar to A.umbrinella (Truong et al. 2017) or herbaria records - I just wasn't sure? I have to assume something like this.
According to the Atlas of Living Australia, (ALA), this fungus appears in Western, South Australia, New South Wales, Queensland, Victoria and Tasmania with observations peaking across the mainland and Tasmania during May, and with a much lower peak during spring - which I assume is with the spring rains in southern Australia (at least at my place that is what I have noticed), reaching the lowest point in December and January - where only Tasmania reported observations are listed.
Species descriptions for Amanita umbrinella are available from Tulloss 2021 Amanita umbrinella here at: http://www.amanitaceae.org?Amanita+umbrinella and also see Gentilli (1953) in the Western Australian Field Naturalists publication that contains a nice clear drawing of the species as well as some of the identification features and the taxonomic history in Australia. Also see the text by Grgurinovic (1997) page 389 under Amanita bambra.
A general description from personal observation and incorporating some existing texts.
cap (pileus)
Gates & Ratkowsky (2014) describes the caps as 'grey-brown' with 'white or pale grey patches' which reflects what I have observed of this species, furthermore descriptions by (Tulloss 2021) include 'cap can range from grayish brown to saturated olive-chestnut, bistre, very dark umber, chocolate, drab hair brown, or olivaceous-black' and Gentilli (1953), 'slightly sticky in wet weather'. The patches on the cap are the volval remnants and eventually these fall away or when touched. I noticed on the immature button I found, that the powdery covering was so fine, it would come off easily. The size of the cap can range up to around 12cm across (Gates & Ratkowsky 2014) becoming flattened with age (Tulloss 2021).
gills
Crowded, light cream, attached or very close to stem (stipe), (see above image A) with Tulloss (2021) stating "gills become purple in exsiccatae; (becoming pinkish/purplish as it dries/is dried)** with very variable spores."
**Interesting that we have this 'pinkish/purplish upon drying' in A.umbrinella and the siimilar looking (similar pigments?) A.rubescens - with pinkish/purplish upon exposure to air. In A.rubescens, apparently due to utilisation of the Tyrosinase enzyme cycle for melanin which first produces a pigment perceived as wine red. The breaking of cells and exposure of their contents to oxygen in the air permits this reaction to take place. Hence, it appears to the observer as a "blushing" reaction. (Tulloss 2021).
A.umbrinella I believe may have a similar type of reaction going on because, this enzyme works at the oxidation of a phenolic compound in the pigment making process (Chen 2005), and what I observed upon cutting open my specimens (Image A) was a really strong phenol smell which I immediately recognized from some Agaricus. Upon dehydrating the collection featured in Image A, I can't say that it looks pinkish/purple-ish - I wonder if this is problematic for my identification.
stem (stipe)
Stipe smokey grey, up to around 10cm L x 3cm W with a striate grey-brown annulus, according to Gates & Ratkowsky (2014).
spores
Spores are white (Gates & Ratkowsky 2014). Gentilli (1953) discusses the spores are hyaline (clear) but when stained with iodine turn brown (no amyloid reaction).
The below images were taken with a generic microscope at varying magnifications. The spores look 'similar' to those illustrated by Gentili (1953). The poor quality of the photographs I have here are unfortunate I think due to the poor quality of the cheap (~$30 mobile phone lense that is attached to the microscope working in tandem with the modest microscope being used. Due to the poor quality of my spore photographs and inability to measure them I cannot be sure it is actually Amanita umbrinella, but perhaps to a 'A.umbrinella grouping' of sorts - please keep this in mind! thank you.
Amanita umbrinella - Lookalikes in Australia
The Australian native Amanita umbrinella, or "Australian Umber Amanita", looks similar to Amanita rubescens, an introduced species to Australia. Amanita rubescens 'The Blusher' is found in deciduous and conifer woodlands, whereas in Australia, Amanita umbrinella is found in native woodlands containing Eucalyptus spp. and/or Nothofagus.
If you are looking for away to tell the difference between the two species, apart from the differing habitat (exotic vs native), is that you will notice that when cutting Amanita umbrinella open, it does not 'blush pink', as does the inner flesh of the 'blusher' A.rubescens, when exposed to air (Wildfoodhuntress). However, when drying, Amanita umbrinella, the gills may display pinkish/purplish hues which is also a helpful way to identify this species.
Apparently, the non-native Amanita rubescens "the blusher' a 'nice tasting, sweet edible mushroom' (WildFoodHuntress 2021), however if you are a person into foraging for wild mushrooms for eating, you absolutely do not want to confuse the two or even 'try out just a bit'. This is because with so little information relatively available on the levels of toxicity of Australian Amanita's - you are likely to be seriously poisoned - because the Amanita genus also contains the most lethal mushrooms in the world including - Amanita phalloides - also known as the Death Cap - which you guessed it, causes death!
The exotic A.rubescens belongs in the Amanita section Validae which contain Haemolytic compounds and A.umbrinella belongs in the Subgenus Amanita, Section Amarrendiae, which is part of Amanita sect. Amanita in the Amanitaceae - of which contain Muscimol and ibotenic acid that can cause severe nervous system and gastrointestinal impact, possibility of coma, fatal in large doses (Tulloss 2021).
Personally I have no interest in eating wild mushrooms, the more I learn about toxicity and the flora and fauna that may rely on these species for their lifecycles and food (such as Amanita umbrinella), it often pains me to take collections for species such as this because I see local wallabies rely on them as part of their diet - they do not have a supermarket to go to like we do! Anyway, sorry, I get passionate! :-)
Amanita umbrinella - Taxonomy & Gondwanan Links
If you like digitised archival records, an interesting recount of the history of how we came to Amanita umbrinella in Australia, using early existing records, including some from Tasmania was done by Gentilli (1953) in the Western Australian Field Naturalists publication Following this link you see a nice drawing of the species as well as some of the identification features and taxonomic history.
As of 2009 in The Checklist of Amanita from Australia and New Zealand, and noted currently on iNaturalist (2021), that this species is organised within the Subgenus Amanita, Section Amarrendiae. This clade includes both sequestrate and truffle-like Amanita species from Australia and South America as well as epigeous (above ground 'mushroom looking') species e.g. Amanita umbrinella from Australia.
The South American sequestrate species Amanita nouhrae, which is mycorrhizal with Nothofagus species,has ornamented basidiospores (see below) that are absent in their closest known relative A. merxmuelleri but present in other described species from the Southern temperate clade such as Amanita umbrinella which is also found in Nothofagus forest (Justo et al. 2010).
It is estimated by Truong et al. (2017), that "the southern temperate clade may have originated near the Eocene/Oligocene boundary suggesting a broadly distributed ancestor in the Southern Hemisphere."
Tulloss (2009) states how the relatively little information around Amanita in Tasmania, is a barrier to a more complete biogeographic picture of the Amanita that partner with Nothofagus trees. Justo et al. (2010) also reminds us that the Australian Amanita genus still needs 'more sampling and sequencing of Australian species needed to help with taxonomic groupings.
Amanita umbrinella could shed further light on sequestrate Amanita evolution.
An interesting 2010 paper Convergent evolution of sequestrate forms in Amanita under Mediterranean climate conditions, by Justo et al. (2010), suggests that the mediterranean climates in southern Europe, northern Africa, and here in Australia, helped the the distantly related Amanita's independently evolve similar traits to adapt to similar conditions during the evolution in of these sequestrate Amanitas.
Within the Amanita, as within some other groupings eg; Boletales and Russulales, there are species that produce 'non-mushroom looking', fruitbodies. These somewhat unusual looking Amanita species have evolved from having fruitbodies with exposed spore bearing structures eg: with gills, to forms that fully enclose the spore bearing surface and that may even reside underground!
Rather than having exposed spore bearing structures eg: gills and forcibly dishcharing theirs spores, they have a closed or even underground habit (truffle-like) in which spores a retained in the fruit-body until it decays or is eaten by an animal (Justo et al. 2010). Also see for an example of truffle-like fungi here.
These sequestrate forms of Amanitas include gasteroid forms (in the same broad group as: truffle-like fungi, puffballs and stinkhorns) and secotioid forms (which look like an intermediate between the gasteroid 'fruffle-like' fungus and your standard "mushroom shaped" ancestors (Justo et al. 2010). For example in some of these types of fungi, the gills (lamellae) are convoluted and anastomosed (fused together to form a network), and if it has a kind of 'mushroom shaped' fruitbody, you may see the margin of the cap does not break free from the stipe (or if it does, the cap never fully expands), (Justo et al. 2010).
In Australia, Torrendia and Amarrendia species (which will each be renamed as Amanita sp.) account for the 'non-mushroom looking shaped' (secotioid and gasteroid) species of Amanitas found here. Whilst these species may look completely different, it is interesting to remember they are related to and they occur within, the same groups of Amanita species that take the familiar mushroom form - that many of us are used to seeing.
In their study, Justo et al. (2010), discuss how Australian species of Amanita are underrepresented in the current dataset, and that more extensive sampling and sequencing of Australian taxa is necessary to investigate the identity of possible agaricoid relatives (or members) of the Amarrendia clade and they mention that sampling of A.umbrinella may assist with this.
Some researchers (Thiers 1984) suggest the advantage of these non-mushroom shaped forms help protect against loss of moisture under unfavorable conditions (extreme drought or cold) and that the intermediate 'secotiod' forms would not be able to disperse as much as other types that get the help of air and animals - losing out in natural selection Bruns et al. 1989 in (Justo et al. 2010).
NB: I am no expert, I try to do my best with information at hand, I do make mistakes so please let me know if I have.
References:
Chen, L., Nicholas, H. & Oberlies, (2005). The most widely recognized mushroom: Chemistry of the genus Amanita, Life Sciences, v.78, iss. 5, pp. 532-538, ISSN 0024-3205,
https://doi.org/10.1016/j.lfs.2005.09.003.
Gates, G. & Ratkowsky, D. (2014). A Field Guide to Tasmanian Fungi, Tasmanian Field Naturalists, Hobart.
Gentilli, J. (1953) Amanitas from King's Park Perth - Amanita umbrinella: Gilbert et Cleyland, Western Australian Naturalist, v.4, no.3, December 21, (1953-1955) pp.59 - 61, https://www.biodiversitylibrary.org/page/58980663
Grgurinovic, C. A. & Flora and Fauna of South Australia Handbooks Committee. & Botanic Gardens of Adelaide and State Herbarium. (1997). Larger fungi of South Australia / by C.A. Grgurinovic Botanic Gardens of Adelaide and State Herbarium and Flora and Fauna of South Australia Handbooks Committee Adelaide.
Justo, A., Morgenstern, I., Hallen-Adams, H. E., & Hibbett, D. S. (2010). Convergent evolution of sequestrate forms in Amanita under Mediterranean climate conditions. Mycologia, 102(3), 675–688. https://doi.org/10.3852/09-191
Tulloss R.E. (2021). Amanita umbrinella. in Tulloss RE, Yang ZL, eds. Amanitaceae studies. http://www.amanitaceae.org?Amanita+umbrinella accessed December 17, 2021.
Tulloss, R.E. (2009). Checklist of Amanita from Australia and New Zealand,
Truong, C., Santiago Sánchez-RamÃrez, Francisco K., Kaplan, Z. Smith, M.E. (2017). The Gondwanan connection Southern temperate Amanita lineages and the description of the first sequestrate species from the Americas, Fungal Biology,Volume 121, Issue 8,2017,Pages 638-651.
Wild Food Huntress (2021) Amanita rubescens
https://www.thewildfoodhuntress.com.au/amanita-rubescen