The terms mildew, mould and fungus (plural is fungi) confuses some non-biologists. Mildew and mould are common names used to refer to those fungi whose body is made of a network of filaments (referred to as mycelium; plural, mycelia). Although the term mildew is occasionally used to refer to fungi that grow in indoor environment and on fabrics, it refers to a plant disease where the fungus causing the disease is seen as a growth on the surface of the host; for example, powdery mild and downy mildew.

Mould is sometimes combined with adjectives to refer to some common moulds. For example: black-mould (Aspergillus niger), blue-mould of citrus (Penicillium italicum), blue-mould of apple (Penicillium expansum); green-mould of citrus (Penicillium digitatum), bread-mould (Chrysonillia sitophila, Rhizopus, Mucor), grey-mould of snowdrop (Botrytis cinerea), white-mould of sweet pea (Hyalodendron album), tomato leaf-mould (Fulvia fulva), and pin-mould (Mucor and other related moulds). The term mould can be spelt with or without a “u” depending on whether one is using British or American English.

Fungi include yeasts (which are non-filamentous and therefore not moulds), moulds/mildew, tree bracket fungi, the truffles and the mushrooms.


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