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Almond MushroomAgaricus subrufescens(but also Agaricus blazei Murill, Agaricus brasiliensis, and Agaricus rufotegulis depending on who you ask)
Kingdom: Fungi
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| Common name | Almond Mushroom |
| Scientific name | Agaricus subrufescens |
| AKA | Royal Sun Agaricus, Mushroom of the Sun, God's Mushroom, Himematsutake, ABM, Cogumelo do Sol (and several more) |
| Season (UK) | Summer to autumn (typically June to October; warmth-dependent, erratic in cooler years) |
| Habitat | Rich soil, compost heaps, woodchip mulch, gardens, disturbed ground; occasionally woodland edges |
| Cap diameter | 5cm to 18cm; hemispherical when young, convex to flat as it ages |
| Spore print | Chocolate brown |
| Edibility | Edible and choice (but cook thoroughly, do not eat raw) |
| Rarity | Uncommon, but increasing (more frequently cultivated than foraged wild) |
The Agaricus genus contains some of Britain’s most reliably excellent edible fungi: the field mushroom; the horse mushroom; the Prince, but also the Yellow Stainer, which is toxic, and causes gastrointestinal symptoms severe enough to end a foraging trip somewhat abruptly. The key across the whole genus: edible species smell of almonds, anise, or clean earthiness; the Yellow Stainer smells of chemicals, printer ink, or phenol.
Think: If it smells like a printer cartridge, it’s wrong.
Overview
Here’s the thing about the almond mushroom: it looks exactly like a mushroom. Not in the way that many wild fungi look mushroom-adjacent if you squint, in a way that suggests it could’ve rolled off a supermarket conveyor belt. Creamy-white to pale tan cap, pink-to-brown gills, thick white stem with a ring. It is a close cousin of the Platonic supermarket mushroom, the button mushroom, and if you found one on a canal towpath and showed it to someone without mycological knowledge, they’d tell you it was probably fine to put it in an omelette, and they wouldn’t necessarily be wrong.
What separates it from the clingfilmed button mushroom, its close relative agaricus bisporus (the most commercially cultivated mushroom on earth) is the smell. The almond mushroom smells powerfully of almonds (shockingly). Specifically marzipan, according to most sources: sweet, and slightly synthetic - unmistakable once you’ve encountered it. The scent comes from benzaldehyde, benzyl alcohol, benzonitrile, and methyl benzoate, if you want the chemistry (you don’t need the chemistry, but it’s always nice to have). You just need to have smelled marzipan at some point in your life, which, given our magnificent cake-based traditions, should be most of us.
It is also, as these things go, an immigrant. Native to North America (first formally described in Connecticut in 1893) it arrived in the UK at some point in the 20th century, and has been quietly establishing itself in gardens, compost heaps, and disturbed ground with the same vaguely annoying confidence of many American imports. Wild Food UK rates it as uncommon but increasing.
We have found it, for what it’s worth. It looks like a mushroom. It smells like a Bakewell tart.
Forager Note: The yellow-staining test is the single most important check in this genus. Press or cut the cap surface and the stem base: in the Yellow Stainer (Agaricus xanthodermus), both stain bright, chrome-yellow immediately and persistently. In the almond mushroom, there may be a faint yellowish tinge that fades to brown (not the same thing at all). If in any doubt, smell it. The yellow stainer smells of phenol. The almond mushroom smells of marzipan. These are not similar smells, if you believe them to be, the problem is with you, not the mushroom.
Identification
The cap is generally between 5cm and 18cm across, starts hemispherical, and flattens to broadly convex with age. Colour ranges from white to pale greyish-brown to dull reddish-tan, with the surface initially covered in fine silky fibres that break into small scales as the cap expands. The margin sometimes splits in older specimens. The overall impression is of something that has been slightly roughed up by weather, which is not a bad description of most things found in Britain.
Gills are free from the stem, crowded, and run through a characteristic colour progression: pale pink in young specimens (protected by the partial veil), deepening through brown to chocolate-brown as the spores mature. This pink-to-brown gill transition is one of the most reliable fresh identification features in the genus generally and worth checking in any unknown Agaricus specimen.
The stem is between 5cm and 12cm tall, stout, white to pale cream, with a slightly bulbous base and a prominent, thick, floppy ring with woolly scales on the underside. Wild Food UK’s description of it as ‘thick and floppy’ is accurate and feels needlessly personal. The flesh is white throughout, firm, and smells of almonds. Cut the stem base: it should remain white or turn very faintly pinkish. Yellow is wrong. Bright, persistent, immediate yellow is very wrong.
White-to-tan scaled cap, pink gills turning chocolate-brown, floppy ring, marzipan smell, white flesh that doesn’t stain yellow. A very mushroomy looking mushroom. That’s the checklist.
Important: The Almond Mushroom contains agaritine, a naturally occurring compound that is significantly reduced by thorough cooking. Do not eat this species raw. This applies to the whole Agaricus genus to varying degrees.
Lookalikes & ‘Mix-Up’ Species
The almond mushroom sits in a genus with several excellent edible relatives (and one genuinely unpleasant toxic one, but we all have that relative). Knowing the family is more useful than memorising the individual species in isolation.
Yellow Stainer (Agaricus xanthodermus) — the one that matters. Responsible for the majority of UK mushroom poisoning cases. Not deadly, but causes severe gastrointestinal symptoms and looks, to the inattentive eye, like a perfectly edible Agaricus. Stains a bright yellow when the cap or stem base is cut or damaged. Smells of printer ink (nothing like almonds). Do the smell test, and the cut test, and you will not confuse these two species. Skip either and you might spend time in A&E at worst, and the loo at best.
The Prince (Agaricus augustus) — close relative, similar almond scent, considerably larger, darker brown scaly cap. Also an excellent edible. The Prince tends to fruit singly or in small groups; the Almond Mushroom more often in larger clusters. If you’ve found something in this territory that smells right, you’ve almost certainly found something worth eating.
Horse Mushroom (Agaricus arvensis) — grassland species, anise-scented, similarly excellent. Larger than a field mushroom, found in open pasture rather than disturbed ground and compost. Also stains slightly yellow but slowly and palely — not the immediate vivid chrome-yellow of the toxic species.
Button Mushroom (Agaricus bisporus) — the supermarket one. If you find what you think is an Almond Mushroom and it smells of nothing in particular, consider the possibility that it came from a packet. Unlikely in the field but worth acknowledging.
Edibility
Choice edible, and one of the better wild fungi available in Britain, by which we mean both the flavour and the texture hold up to cooking in a way that a significant number of more celebrated species don’t. The taste is sweet and nutty, described consistently as a more interesting button mushroom, which undersells it slightly. There’s earthiness underneath, the sweetness that makes it genuinely useful in the kitchen rather than just interesting as a foraging curiosity. The almond smell largely dissipates during cooking, and what you’re left with is the flavour, which is its own reward.
Use it anywhere you’d use a button mushroom or portobello: sautéed in butter, in risotto, in pasta, in a pie, you know the stuff. It holds its texture reasonably well, and doesn’t release excessive moisture. Younger specimens are preferable to older ones on both texture and bug-infestation grounds (older Agaricus species in general are more likely to be hosting residents).
Cook it thoroughly.
A note on the medicinal supplement market, which keeps coming up: the almond mushroom is sold in supplement form as ABM (Agaricus blazei Murill - an outdated name, kept deliberately by the industry) and marketed for purported anti-cancer and immunomodulatory properties. No long-term, large-scale human clinical trials establish these claims to the standard required for medical recommendation. To quote Tim Minchin - “you know what they call alternative medicine that’s been proven to work? Medicine.” The FDA has actually had to issue warning letters to companies making specific disease-treatment claims. It tastes good. Cook it. It’s probably good for you in a general sense.
Naming history
The almond mushroom was first formally described in 1893 by Charles Horton Peck, a New York State Botanist and prolific describer of North American fungi. The man was responsible for formally documenting somewhere in the region of 2,500 species during his career, which must have taken a while. Peck collected his type specimens in Connecticut, and named the species Agaricus subrufescens, ‘somewhat reddish’ in Latin, referring to the cap colouration. This name, by the rules of taxonomic priority, is the one that should be used. It mostly isn’t.
In the 1970s, a Japanese researcher cultivated a strain of the mushroom in Brazil (in the São Paulo region), where it had been introduced and grown as Cogumelo do Sol or ‘Mushroom of the Sun’. He described it as a new species: Agaricus blazei Murill. This name spread through the medicinal mushroom industry globally, and became the name under which the majority of research into the species’ bioactive properties was published. It is Agaricus blazei Murill that’s on most supplements - this is taxonomically incorrect, having been shown by genetic testing to be identical to Peck’s 1893 subrufescens, but likely purposefully.
The common name ‘almond mushroom’ is the most widely used in English-language foraging contexts, and the one used by Wild Food UK. ‘Royal Sun Agaricus’ is the trade name, ‘God’s Mushroom’ and ‘Mushroom of Life’ are names from Brazilian folk tradition that found their way into supplement marketing (and have overstayed their welcome). Himematsutake, or ‘princess matsutake’ in Japanese is another, charming nickname, though it has nothing to do with the matsutake mushroom. That’s Japanese nomenclature for you.
The researcher who did the definitive genetic work (Richard Kerrigan) also established that Agaricus brasiliensis (another name in circulation) and Agaricus rufotegulis (the European form) were the same species. Four names; one mushroom; the oldest is correct; the supplement industry has decided this is not their problem. Taxonomy is a conversation, we guess.
Ecology
The almond mushroom is saprotrophic, meaning it feeds on decaying organic matter, rather than forming mycorrhizal partnerships with tree roots. This makes it unusually flexible in habitat terms, and specifically comfortable in the kind of disturbed, enriched ground that humans create: compost heaps, garden beds, woodchip mulch, path edges where organic matter accumulates, disturbed soil near buildings. Wild Food UK notes it forms fruit bodies singly or in clusters in leaf litter or woodchip, which means, in practice, it turns up where you’re not necessarily expecting anything.
It requires warmth to fruit, being native to the northeastern United States, it prefers temperatures of roughly 20 to 25°C which, in Britain, means it’s a summer-to-early-autumn species and highly dependent on the year. In a cool British summer it may not appear at all. In a warm one, and warm ones are, all available evidence suggests, becoming more common, it can be quite productive. Warming conditions are gradually making more of Britain hospitable to a species that was previously marginal, so, you know, winning?
It does not grow on logs, or woody substrate, one of the few Agaricus species for which this is explicitly noted in cultivation guides. This limits where it establishes naturally, but also makes it a good candidate for garden cultivation, which is part of why UK records are increasing: some ‘wild’ finds are almost certainly garden escapees.
Where to Find It in the UK
Harder to pin to specific locations than most, because the almond mushroom is less a woodland species than an opportunist. Effectively, it turns up where conditions are right rather than in defined habitat types. Wild Food UK’s range description is ‘uncommon but increasing across the British Isles’, and the NBN Atlas reflects scattered records across England and Wales with no obvious concentration (consistent with a species spreading from cultivation and garden establishment rather than from a natural range).
Practically: look in gardens with well-maintained compost heaps, in allotment sites, in parks and urban green spaces where woodchip mulch is used, and on the margins of paths through disturbed ground (near human habitation). The south of England produces more records than the north (warmer summers, more consistent fruiting conditions) but it has been found as far north as Scotland. Urban parks in London and the Southeast are plausible spots in a warm year.
The season for this mushroom runs (generally) between June and October in a good year, with July to September most productive. It needs warmth and moisture together which, in Britain, means you’re dependent on the weather cooperating. Maybe we have more in common than we thought. In practice, it’s more reliably found by cultivating than foraging, as it grows readily on compost substrate and produces well in a garden setting. Less exciting from a foraging perspective. Considerably more reliable.
If you’ve found one in the north of England, Scotland, or Wales, consider reporting it to the NBN Atlas or the British Mycological Society. Range records for uncommon increasing species are genuinely useful data. More useful, certainly, than a foraging article on the internet, including this one.
Worth knowing
The almond mushroom was cultivated commercially in the United States from the late 19th century through the early 20th century, where it was grown and sold as a choice edible in the Atlantic states. It was then essentially abandoned in favour of Agaricus bisporus, the common button mushroom, which is blander, less aromatic, and considerably less interesting - something similar happened to American culture more broadly. The reasons for this switch are not well documented, but the leading theory is that some consumers found the almond extract smell off-putting. If true, this is one of the more baffling collective aesthetic decisions in the history of food production. The button mushroom has been commercially dominant ever since. There you go: the almond mushroom smells of marzipan and nobody wants it.
The supplement industry’s attachment to the name Agaricus blazei is, we suspect, mostly cynical. We find this irritating in a way that probably says more about us than anything.
As for the tshirt question: no. An Almond Mushroom on a tshirt looks like a button mushroom on a tshirt, which looks like someone was inattentive while eating a pizza. The Agaricus genus has a branding problem as far as we’re concerned — it looks too much like food. Commercially excellent for supermarkets, but less useful for us. There are over 15,000 fungal species in the UK, this one will be in the bottom half of the list for tshirtification.
Sources: Wild Food UK, The Wildlife Trusts, First Nature, Woodland Trust, NatureSpot, Wikipedia (Agaricus subrufescens), Mushroom Appreciation, NBN Atlas
This article is for informational purposes only. Never consume any wild mushroom without a confirmed identification from a qualified expert. Several Agaricus species are toxic. Nothing in this entry constitutes medical or dietary advice, including the observations about the supplement industry, which were editorial opinion and should be taken as such (true, though).