Basidiomycetes are a group of fungi known for their distinctive reproductive structures called basidia, where spores are produced. This class includes familiar organisms such as mushrooms, puffballs, and shelf fungi. They play essential roles in ecosystems as decomposers, breaking down organic matter and recycling nutrients. These fungi can be found in various habitats, from forests to grasslands. Some basidiomycetes form symbiotic relationships with plants, known as mycorrhizae, which help plants absorb water and nutrients. Others can be pathogenic, causing diseases in plants and animals. Overall, basidiomycetes are vital for maintaining ecological balance.