Phycomycetes

The Phycomycetes class of fungi has three subclasses: Chytridiomycetes, Zygomycetes, and Oomycetes. All are coenocytic and nonseptate, and many are tubular. The only cross walls are those formed at the bases of sporangia and gametangia. In the perfect stage, a zygospore or an oospore is produced. The name Phycomycetes means “alga-like fungi,” although this does not mean that these fungi derive from algal ancestors. Rather, many mycologists consider these fungi to have evolved from protozoa.