Phyletic Considerations of the Harpellales and Asellariales (Trichomycetes, Zygomycotina) and the Kickxellales (Zygomycetes, Zygomycotina)

SUMMARY

The Harpellales, Asellariales (Trichomycetes) and Kickxellaceae (Zygomycetes) share several characters which separate them from the other trichomycete orders, Amoebidiales and Eccrinales, as well as all other members of the Zygomycotina. The relatively complex septal apparatus comprising a crosswall with a central pore occluded by a biumbonate plug, the fundamentally coemansioid form of the asexual reproductive apparatus, similar wall structure, serological affinity and the labyrinthiform organelle (Kickxellaceae) or trichospore appendage(s) (Harpellales) could indicate a close phyletic relationship. A putative phyletic series based essentially upon the morphology of these fungi is proposed and the evidence for their relationship assessed.