What basis were the fungi included in the Plant Kingdom?

Fungi grow out of the ground (and on other substrates) and have rigid cell walls so were initially classified as a Phylum of the Plant Kingdom. Carl Linnaeus used mostly gross morphological features to determine his classification scheme. read more

Most fungi build their cell walls out of chitin. This is the same material as the hard outer shells of insects and other arthropods. Plants do not make chitin. Fungi were previously included in the plant kingdom, but are now seen to be more closely related to animals. read more

Single-celled eukaryotes were classified as plants or animals on the basis of which type of cell they most resembled. I was first taught a five kingdom system: plants, animals, fungi, protoctists (all eukaryotes not fitting into the other three categories) and bacteria. read more

A fungus (plural: fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from the other eukaryotic life kingdoms of plants and animals. read more