Scientists Say: Fungi

The fungi kingdom includes mushrooms, molds, yeast and many other organisms

wooden boxes on a table are filled with smaller cardboard boxes with different types and colors of mushrooms

The most familiar form of fungus for many people may be mushrooms. Although some mushrooms are poisonous, many others are tasty and safe to eat.

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Fungi (noun, “FUN-gee” or “FUN-jai”)

Like plants or animals, fungi are a distinct form, or kingdom, of living things. Yeast, mold, mildew and mushrooms are all fungi. Lichens seen growing on trees and rocks are also half-fungus. For a long time, such life forms were thought to be plants. In turns out that fungi are actually more closely related to animals.

Fungi are eukaryotes. That is, their cells store DNA in pouches called nuclei. Some fungi, like yeast, are single-celled. But most fungi, such as mushrooms, are made of many cells. More than 100,000 species of fungi are known. But millions are thought to exist.

Like animals, fungi get their food from other organisms. They ooze enzymes that break down organic matter around them. Fungi can then absorb those small molecules as food. Some fungi feed on dead plants or animals. Such decomposers help recycle nutrients through ecosystems. Other fungi feed on living things. Some are parasites, such as the fungi that grow inside ants and sprout from their heads. In humans, fungi can cause infections like athlete’s foot and ringworm.

Some fungi are also poisonous if eaten. But other fungi have formed partnerships with plants or animals. Some live inside plant roots. These fungi supply those plants with nutrients from the soil. Others can help keep the human gut healthy. People also eat non-poisonous mushrooms and use yeast to make bread. Some fungi even produce medicines, such as the antibiotic penicillin.

In a sentence

The king of all fungi is the “Humongous Fungus” — a single fungus of the species Armillaria ostoyae, which spans nine square kilometers (3.5 square miles) in Oregon.

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Maria Temming is the Assistant Managing Editor at Science News Explores. She has bachelor's degrees in physics and English, and a master's in science writing.