Toadstools and mushrooms are types of fungi, not plants. They belong to the kingdom Fungi, which is separate from the plant kingdom. Fungi are heterotrophic organisms, meaning they obtain nutrients by absorbing organic matter from their environment, unlike plants that produce their own food through photosynthesis.

• Fungi: A kingdom of organisms that includes mushrooms, toadstools, yeasts, molds, and mildews. Fungi are characterized by having cell walls made of chitin and obtaining nutrients by absorption.
• Mushrooms: The fleshy, spore-bearing fruiting body of a fungus, typically produced above ground or on its substrate.
• Toadstools: Generally refers to poisonous or inedible mushrooms. However, there is no scientific distinction between mushrooms and toadstools; the term "toadstool" is often used to describe fungi that are considered undesirable for consumption.

For more information, you can refer to these resources:

• Britannica - Fungus
• Diffen - Fungus vs. Plant