Learn — The Fungi Kingdom
The Kingdom that
sustains life
More closely related to animals than to plants. Older than the dinosaurs. More essential than any other form of life on Earth.
What is a fungus?
A fungus is neither a plant nor an animal: it is a kingdom of its own. The Fungi Kingdom encompasses eukaryotic organisms —with a defined cell nucleus— that lack chlorophyll and therefore cannot photosynthesize. They have no roots, stems or leaves; nor do they move. Yet what they do is extraordinary: they decompose, connect, nourish and transform every ecosystem they inhabit.
Characteristics that define fungi
- Eukaryotic: their cells have a membrane-bound nucleus, unlike bacteria.
- Heterotrophic: they do not produce their own food. They obtain energy by decomposing external organic matter.
- Chitin cell wall: the same material that forms the exoskeleton of insects, not cellulose as in plants.
- Reproduction by spores: they release millions of microscopic spores capable of surviving extreme conditions.
- No differentiated tissues: they have no organs or nervous system, yet they display complex forms of chemical communication.
Morphology: how they are built
The fundamental structural unit is the hypha: a microscopic tubular filament that grows at its tip and branches continuously. The mass of hyphae forms the mycelium, which generally lives hidden underground, in wood or in the substrate that feeds it.
What we commonly call a «mushroom» is in fact the fruiting body or sporocarp: the reproductive structure the mycelium produces to release spores. It is equivalent to the fruit of a tree. The real organism lives beneath the surface.
Parts of a typical fruiting body
- Pileus (cap): protects the gills and maximizes spore dispersal.
- Gills or pores: the surface where spores are produced and released.
- Stipe (stem): supports the cap and connects to the mycelium.
- Ring (annulus): a remnant of the partial veil. Key in identifying Amanita.
- Volva: a basal sheath present in Amanita; diagnostic of the deadly species.
- Spores: their color, shape and size are fundamental diagnostic tools.
How they feed: external digestion
Fungi are chemoorganotrophic heterotrophs: they obtain energy by decomposing organic compounds through external digestion. They secrete enzymes into the environment —proteases, cellulases, ligninases— that break complex molecules into simple ones absorbable through their cell wall. [2]
Nutritional types
- Saprotrophs: they break down dead organic matter. The planet’s great recyclers. Examples: Pleurotus ostreatus (oyster mushroom), Lentinula edodes (shiitake).
- Mycorrhizal: mutualistic associations with plant roots. Ninety percent of land plants depend on them. [3] Examples: Boletus edulis (porcini), Cantharellus.
- Parasites: Cordyceps parasitizes insects with behavioral-control strategies over its host.
- Endophytes: they live within plant tissue without causing disease. Their ecological role is under active investigation.
Ecology: the invisible infrastructure of life
Without fungi, the carbon, nitrogen and phosphorus cycles would grind to a halt.
The Wood Wide Web
Ecologist Suzanne Simard documented that the trees of a forest are connected through mycelial networks that allow the exchange of nutrients, water and chemical alarm signals between individuals. [4] Mycorrhizal fungi are the cables of that network.
Decomposition and the carbon cycle
Lignin is practically indigestible for most organisms. Only white-rot fungi (such as Ganoderma lucidum) possess the enzymes able to break it down completely, returning that carbon to the cycle. [5]
Soil formation
The mycelium secretes organic acids that dissolve minerals from the parent rock. Healthy forest soils hold kilometers of mycelium per gram of earth.
Classification of the Fungi Kingdom
Basidiomycota
The most visually diverse group. It includes most edible, medicinal and poisonous mushrooms. They produce spores on basidia. Examples: Agaricus, Lentinula, Ganoderma, Trametes, Inonotus, Cantharellus.
Ascomycota
The largest phylum by number of species. It produces spores in asci. It includes truffles, morels and yeasts: Morchella, Tuber, Saccharomyces cerevisiae.
Mucoromycota
Fast-reproducing fungi. The genus Rhizopus makes tempeh. Many form arbuscular mycorrhizae with plants.
Nomenclature and the kingdom's databases
Classifying is one thing; naming is another. A scientific name is not born in a book: it is born in a registry. Since 1 January 2013, the International Code of Nomenclature for algae, fungi, and plants (Article 42) requires every new fungal name to be registered before it is published, in one of the three repositories the Code recognizes; if it is not registered, the name does not exist for science. Since 2019 the same rule extends to type designations. These are the doors where it is decided what each fungus is called — and where it lives.
The registry where every new fungal name is legally born. One of the three repositories recognized by the Code, alongside Index Fungorum and Fungal Names.
The global nomenclator: who named what, where and when. Published by the Royal Botanic Gardens, Kew.
The checklist of accepted names. Index Fungorum gives the name; Species Fungorum says which one is correct when several are in dispute.
Where each species lives on the planet. More than 60 million fungal records, georeferenced and open access.
The consensus catalogue of all known life. Its fungal component is supplied by Species Fungorum.
The mycology journal of the Mexican Association for the Study of Fungi. Peer-reviewed, open access and in Spanish.
The encyclopedia of Mexican biodiversity, from CONABIO. This is where you look up what lives in our territory and what it is called here.
Mexican citizen science. Home of the Fungívoros de Simbiosis project: every mushroom we find on the tours enters the national record.
Mexico's funga has doors of its own. Three of these eight are Mexican — and there are more: Mexico: Fungi Kingdom holds the national databases for looking up which mushroom is which in our territory.
Categories by relationship with humans
~2,000 documented species. Mexico has more than 350 wild species consumed by Indigenous communities. [6] The Zapotec, Otomí and Mazatec peoples have carried, for centuries, identification systems passed on orally.
Ganoderma lucidum: immunomodulating beta-glucans [7]. Hericium erinaceus: erinacines associated with NGF [8]. Cordyceps militaris: cordycepin acting on energy metabolism [9]. Inonotus obliquus: antioxidant polysaccharides [10]. Trametes versicolor: PSK and PSP in integrative oncology. [11]
~50–100 toxic species; around 20 deadly. Amanita phalloides causes 90% of deaths from fungal poisoning. Its amatoxins damage the liver irreversibly. If you have any doubt, do not eat it. Ever.
The Mazatec have used Psilocybe in ceremonial contexts since before the Conquest. María Sabina introduced these practices to the Western world. Science studies psilocybin in treatment-resistant depression and PTSD. [12]
The mycelium as a network: what we still do not understand
The largest living organism on the planet is a fungus: a mycelial network of Armillaria ostoyae in Oregon covering 9.6 km² with an estimated age of between 2,000 and 8,000 years. [14]
Scientific references
- Hawksworth & Lücking (2017). Fungal Diversity Revisited. Microbiology Spectrum, 5(4). doi:10.1128/microbiolspec.FUNK-0052-2016
- Baldrian & Valášková (2008). Degradation of cellulose by basidiomycetous fungi. FEMS Microbiology Reviews. doi:10.1111/j.1574-6976.2008.00106.x
- van der Heijden et al. (2015). Mycorrhizal ecology and evolution. New Phytologist. doi:10.1111/nph.13288
- Simard et al. (1997). Net transfer of carbon between ectomycorrhizal tree species. Nature, 388. doi:10.1038/41557
- Martínez et al. (2005). Biodegradation of lignocellulosics. International Microbiology. PMID:16200498
- Garibay-Orijel et al. (2006). Understanding cultural significance, the edible mushrooms case. Economic Botany. doi:10.1663/0013-0001
- Boh et al. (2007). Ganoderma lucidum and its pharmaceutically active compounds. Biotechnology Annual Review. doi:10.1016/S1387-2656(07)13010-6
- Mori et al. (2009). Improving effects of Hericium erinaceus on mild cognitive impairment. Phytotherapy Research. doi:10.1002/ptr.2634
- Hirsch et al. (2017). Cordyceps militaris improves tolerance to high-intensity exercise. Journal of Dietary Supplements. doi:10.1080/19390211.2016.1203386
- Géry et al. (2018). Chaga, a future potential medicinal fungus in oncology? Journal of Gastrointestinal Cancer. doi:10.1007/s12029-017-0004-5
- Standish et al. (2008). Trametes versicolor mushroom immune therapy in breast cancer. Journal of the Society for Integrative Oncology. PMID:19087381
- Carhart-Harris et al. (2021). Trial of psilocybin versus escitalopram for depression. NEJM, 384. doi:10.1056/NEJMoa2032994
- Adamatzky (2022). Language of fungi derived from their electrical spiking activity. Royal Society Open Science. doi:10.1098/rsos.211926
- Ferguson et al. (2003). Coarse-scale population structure of pathogenic Armillaria species. Canadian Journal of Forest Research. doi:10.1139/x03-065
Ten doors into the fungal kingdom
Each section is an independent entry point. Start wherever you like — or follow the path from science to the field.
The Fungi Kingdom
The strangest kingdom on the planet. 1.4 billion years of evolution. Why fungi are neither plants nor animals — and why that changes everything.
See the kingdom's biology →
Simbiosis Species
Reishi, Lion's Mane, Cordyceps, Chaga, Turkey Tail, Maitake, Shiitake, and Himematsutake. Full profile: history, biocompounds, and how to take them.
See the 8 species →Biocomponents
Beta-glucans, triterpenes, cordycepin, hericenones, erinacines. What they are, how they act, and why each mushroom has a star molecule. Comparative table by species.
See the active chemistry →
Extraction Methods
Why not all mushroom powder is equal. Hot water, alcohol, dual extraction, ultrasound. Why fruiting bodies are superior to mycelium on grain.
Understand extraction →
Mycotourism & Ethnomycology
The mycological knowledge of Mexico's Indigenous communities is among the richest in the world. Mushrooms, science, art, and community across Mexican territory.
Explore ethnomycology →Mushrooms & Medicine
From penicillin to modern clinical trials. What science says about mushrooms as immunomodulators, nootropics, and adaptogens.
See mushrooms & medicine →Fermentation
Kombucha, kefir, tempeh, miso — and the quiet role of fungi in each. Gastronomy, microbiome, and functional health connected.
Learn about fermentation →Mycoremediation
Fungi break down petroleum, plastics, and toxins. How mycelium is being used to clean contaminated soils, and what that means for the future.
See mycoremediation →Simbiosis Recipe Collections
More than 40 mushroom recipes: wild, functional, fermented, and with guest chefs. Each recipe links directly to the product it uses.
See recipe collections →Consumption Guide
Doses, timing, combinations, time-to-results, and contraindications. Full table by species. No fluff.
See the consumption guide →
The second most biodiverse country in edible mushrooms in the world
Surpassed only by China. Mexico has between 350 and 400 documented species of wild edible mushrooms. Otomi, Mazatec, Zapotec, Purepecha, and Tlahica-Pjak'oo communities have safeguarded this knowledge for centuries.
El Hongosto — the rainy season, from June to October — is one of the country's richest gastronomic and cultural phenomena.
Mexico: Fungi Kingdom →Scientific library
Beyond the references in the text: a selection of peer-reviewed studies and sources to keep reading. Direct links to the original.
Meta-analysis · PMC 2024
Medicinal mushrooms as immunomodulators in chronic inflammation
Systematic review on fungal bioactives and their mechanism of action in inflammation. PMC — NIH.
Read on PMC →Clinical trial · PubMed 2024
Beta-glucans from medicinal mushrooms and innate immunity
Activation of NK, NKT, and T cells with beta-glucans from Shiitake, Maitake, and others. Molecules, 2024.
See on PubMed →Review · Frontiers 2024
Fungal beta-glucans and trained immunity
Mushroom beta-glucans induce immunological memory (Trained Immunity). Frontiers in Nutrition, 2024.
Read on Frontiers →Pharmacology · PMC 2021
Fungal beta-glucans and tumor progression
Mechanisms of action on the immune system and antitumor potential. PMC — NIH.
Read on PMC →Review · PubMed 2009
Hericium erinaceus and mild cognitive impairment
Effects of Lion's Mane on cognition in older adults. Phytotherapy Research.
DOI: 10.1002/ptr.2634 →Clinical trial · PubMed 2017
Cordyceps militaris and high-intensity exercise
Cordyceps improves exercise tolerance. Journal of Dietary Supplements.
DOI: 10.1080/19390211.2016.1203386 →Microbiome · PubMed 2014
Turkey Tail and gut microbiota
Effects of PSK from Trametes versicolor on the human microbiota. Gut Microbes.
DOI: 10.4161/gmic.29558 →Open-access book · NCBI 2011
Ganoderma lucidum (Reishi): full clinical review
Open-access chapter in Herbal Medicine: Biomolecular and Clinical Aspects. Benzie & Wachtel-Galor, NCBI.
Read on NCBI →Biopharmaceutical · PMC 2025
Edible mushrooms as a natural therapeutic platform
Cordycepin, lentinan, Maitake D-Fraction, and Reishi triterpenes as anticancer agents. PMC, 2025.
Read on PMC →Specialized journal · Open access
International Journal of Medicinal Mushrooms
The field's most specialized scientific journal. Fungal pharmacology, clinical trials, and ethnomycology.
See the journal →Recommended library
From the most accessible to the most technical. Curated by Arif Towns Alonso.
For everyone
Entangled Life
Merlin Sheldrake, 2020
The most complete popular-science book on the fungal kingdom. In Spanish as La vida entrelazada. Essential.
For everyone
Mycelium Running
Paul Stamets, 2005
The practical reference on cultivating medicinal and edible mushrooms.
Technical
Medicinal Mushrooms: A Clinical Guide
Martin Powell, 2014
The most thorough clinical manual in English. Doses, interactions, and clinical evidence by species.
Mexico
Hongos de Mexico
Garibay-Orijel et al. — UNAM
Traditional use of mushrooms in Mexican Indigenous communities. Institute of Biology, UNAM.
Documentary
Fantastic Fungi
Louie Schwartzberg, 2019 — Netflix
The reference documentary on the fungal kingdom. Featuring Paul Stamets.
Podcast
Huberman Lab — Adaptogens
Andrew Huberman — Stanford
The Stanford neuroscientist reviews adaptogens and functional mushrooms with scientific rigor.
The deepest learning happens in the forest
Guided foraging tours with mycologists, nanacateras, and chefs. Season June – October.
See Experiences Quiz: Which Mushroom Do You Need?All information on this page is educational. Simbiosis products are dietary supplements not intended to diagnose, treat, cure, or prevent any disease. COFEPRIS.