A fungus is a eukaryotic organism, which is unique. There are at least 1.5 million species of fungi - 6 times more species than plants. being eukaryotic means that similar to animals, fungal cells contain a nucleus rather than free-floating DNA. And like animals, fungi have to ‘eat’ their food, unlike photosynthesizing plants which receive their energy from sunlight. Mushrooms are really somewhere between a vegetable and an animal.
Growing mushroom leather basically involves harvesting a fungi’s mycelium -it's 'root system', which naturally forms a solid foam that can be compressed into a material that resembles leather. Unlike the limited sizing of animal leather, the mycelium can be grown to massive 'hides' up to 27 metres long and 2 metres wide. And unlike many vegan leathers, mycelium doesn’t need PU (polyurethane or plastic) added, to act like leather.
Fungi are really somewhere between a vegetable and an animal. Fungi are often a filamentous web called mycelium, which spread throughout their environments like forest floors, secreting enzymes that dissolve food so that it can be absorbed into their cells. Fungi can eat almost anything – dead or alive and it’s activity is critical to the cycles of life on earth.
If you are buying or using vegan leather, check carefully how it was made to ensure you aren't buying fossil fuel based plastic (unless of course that is your intention). There are an increasing number of non animals 'leathers' that don’t contain plastic – paper, cork, waxed cotton, leaves. If you do buy apple, coffee, recycled rubber, pineapple leathers, in many cases, the plastic binder could actually from recycled plastic, which of course is better than virgin plastic. The way to tell is to simply read the label. If it's recycled, the maker will tell you 99% of the time. Just bear in mind that recycled plastic or not, the product won't break down or biodegrade.