T. pleuroticola T. pleuroti T. amazonicum T. aggressivum T. epimyces T. parepimyces Hypocrea epimyces T. harzianum H. straminea H. catoptron H. cupularis H. lixii T. dacrymycellum T. cinnamomeum T. stramineum Most Trichoderma strains have no sexual stage but instead produce only asexual spores.

Traditional taxonomy was based upon differences in morphology, primarily of the asexual sporulation apparatus, but more molecular approaches are now being used.

Various asexual genetic factors, such as parasexual recombination, mutation and other processes contribute to variation between nuclei in a single organism (thallus).

While wild strains are highly adaptable and may be heterokaryotic (contain nuclei of dissimilar genotype within a single organism, and hence highly variable), strains used for biocontrol in commercial agriculture are, or should be, homokaryotic (nuclei are all genetically similar or identical).

This is an extremely important quality control item for any company wishing to commercialize these organisms.

They have evolved numerous mechanisms for both attack of other fungi and for enhancing plant and root growth.