form one of the three kingdoms of multicellular organisms, alongside the plant and animal kingdoms, but are actually rather more closely related
to animals than to plants. Lichens are a fascinating symbiosis between a fungus partner and a photosynthetic organism, usually an alga, and these are covered on our page here
Fungi are not photosynthetic, and like animals are heterotrophs
. Most are saprophytic relying on breaking down dead material to obtain their nutrition, and without them the world's ecosystems would collapse. Some however are partasites, or pathogenic to plants and animals, and others have a special symbiotic relationship with plants, by assisting their uptake of water and nutrients.
Types of fungi
There are 8 currently recognised phyla of fungi, but those of interest to us are in the sub-kingdom Dikarya
, which includes the Basidiomycetes
(mushrooms and their relatives) and Ascomycetes
, the less conspicuous cap fungi, antibiotic producers likei and pathogens like Candida
, scabs, ergot and mildew. There are about 64,000 ascomycetes, and roughly half that number of basidiomycetes described globally. Becaause fungal classification is so tricky, we will not describe them by group, but instead by their role in the garden.
Most fungi are tiny and/or inconspicuous, and generally are only seen when they enter their reproductive phase, producing spore carrying structure like muschrooms. The fundamental body structure is very thin filaments of tissue called hyphae, individually only one hundredth of a millimetre thick, but often growing together into strands, and many centimetres long. These are formed when a spore germinates, and both spore and hyphae are haploid. (See our page on ferns
for some explanation of this). Hyphae grow at the tip, and are continually forking to create a net-like mass of tissue or mycelium, permeating through the substrate in which they live. When the mycelium appears on a surface, it is usually termed a mould.
Fungal classification is based on their reproductive structures. They use both asexual reproduction using spores and mycelium fragmentation, and a horrendously complicated array of sexual mechanisms. You really have to be tough to be a mycologist.
The most familar fungal structure is the basidiomycete fruiting body known as a mushroom, toadstool - or just "fungus", but this is nourished by and grows from an invisible mass of mycelium underneath. This usually has "gills" underneath, from which reproductive spores are released. These fruiting bodies can however have a remarkable range of shapes and colours.