This research focused on distinguishing different species within a group of closely related fungi called Trichoderma viridescens. Using genetic analysis and detailed microscopic examination, the researchers identified 13 distinct species that look very similar but are genetically different. This work helps mycologists and other scientists accurately identify these fungi, which is important for both research and practical applications. Impacts on everyday life: – Improves our ability to correctly identify fungi that may be beneficial or harmful in agriculture and industry – Helps understand biodiversity and evolution of fungi in natural environments – Provides tools for quality control in biological products that use these fungi – Enables better monitoring of fungal populations in environmental and clinical settings – Aids in developing targeted applications of beneficial Trichoderma species in agriculture and biotechnology