Soil fungi are microscopic plant-like cells that grow in long threadlike structures or hyphae that make a mass called mycelium. The mycelium absorbs nutrients from the roots it has colonised, surface organic matter or the soil. It produces special hyphae that create the reproductive spores. Some fungi are single celled (eg yeast). Fungi have many different structures but they can act in similar ways and thus are not as plant specific in their needs as some soil bacteria such as Rhizobia.