Microfungi
（重定向自Microfungus）
Microfungi are fungi, eukaryotic organisms such as molds, mildews and rusts, which exhibit tube tip-growth and have cell walls composed of chitin, a polymer of N-acetylglucosamine. The microfungi are an artificial, paraphyletic group, distinguished from macrofungi only by the absence of a large, multicellular fruiting body. Microfungi are ubiquitous in all terrestrial and freshwater and marine environments. Microfungi grow in plants, soil, water, insects, cattle rumens, hair, and skin. Most of the fungal body consists of microscopic threads, called hyphae, extending through the substrate in which it grows. The mycelia of microfungi produce thousands of tiny spores that are carried by the air, spreading the fungus.