Fungus

A fungus is an organism belonging to the Fungi, one of the five kingdoms in Linnaean taxonomy. Varieties of fungus are used as human food, including shiitake mushrooms and Mexican corn smut. Some varieties infest humans, other mammals, insects and birds, with results varying from mild itching to death.

The Fungi kingdom contains the divisions :

• Division Chytridiomycota
• Division Zygomycota
• Division Ascomycota
• Division Basidiomycota
• Division Deuteromycota: fungi of uncertain placement, grouped for convenience

The chytrids are sometimes placed among the Protista, thanks to their relatively simple organization, but are of definite relation to the other fungi. Alone among the fungi, they produced flagellate spores, which characteristically have a single posterior flagellum. This, the common presence of chitin, and other ultrastructure suggest fungi arose from the same ancestral stock as animals and choanoflagellates.

Lichens are a long-standing symbiotic relationship, formed between a fungus and a green alga or a cyanobacterium. Lichens are named based on the fungal component, typically a member of the Ascomycota, rarely a member of the Basidiomycota. Some place lichens in their own phylum (Mycophycophyta) but this ignores the fact that the components belong in separate lineages.

See also: hypha, mycorrhiza, mycelium, puff-ball

Fungal diseases include;

• Honey fungus
• Chestnut blight

Fungal infections may also be a factor in causing Specific replant disease