Researchers found that certain fungi called Fusarium species can infect cannabis flowers growing in greenhouses and produce harmful toxins called mycotoxins. These toxins, which can accumulate in dried cannabis buds, come from both direct infection and from nearby tall fescue grass plants growing outside the greenhouse. The study shows that high humidity conditions in greenhouses can promote fungal growth and toxin production, potentially affecting cannabis safety. Different cannabis varieties showed varying levels of toxin accumulation despite similar fungal infection rates.