The other main difference between plants and fungi is that all plants have a cell wall composed to cellulose. While fungi do have a cell wall, it is composed of a different substance called chitin. Chitin is the same molecule that makes up the exoskeletons of insects.
Although when we think of fungi we envision mushrooms, this is not the main part of the fungi. The mushroom is strictly a sexual organ, like a flower on a plant. It only appears when a fungus is ready to produce spores. The rest of the fungus, called the mycelium, generally looks like a mass of thread-like tendrils. The mycelium is rarely seen because it is normally underground or within what it’s decomposing.
Fungi are important because not only do they decompose dead organisms and release the nutrients trapped within, they are actually necessary for many plants to grow in the first place. For example, for a very long time cultivating orchids was nearly impossible, and nobody was quite sure why. The reason turned out to be that the orchids required a fungal symbiont to successfully germinate by providing it with food. An orchid seed is so small that without it’s fungus it doesn’t have enough food to survive, and the fungus continues to help it even after it has established by providing certain nutrients. It has recently been discovered that almost all plants have at least some fungal symbionts that help it survive. Although not all are as dependent on their fungi as orchids are, many plants would surely not exist if it were not for their fungal partners. Do the gesneriad depend on fungal partners???
Many, many thanks to Scientist Lynn for making this understandable!