Endophytic fungi are a highly diverse group of fungi, primarily ascomycetous, belonging to a polyphyletic group. Their presence in asymptomatic plant tissues defines their functional characteristics. These fungi live in healthy plants’ aboveground tissues, do not seem to generate illness symptoms, and might even benefit their hosts. The four types of endophytes that have been identified include clavicipitaceous endophytes, nonclavicipitaceous endophytes that colonize the entire plant, nonclavicipitaceous endophytes that colonize shoots, and nonclavicipitaceous endophytes that colonize roots. Over the past 20 years, endophytic fungi have attracted much attention due to their propensity to produce physiologically active compounds and their abundance of useful secondary metabolites. They can also create substances that are related to those of their host plants. Certain endophytic fungi can produce the same bioactive substances as the plants they live on. Every land plant that has been investigated thus far, including the genus Lycopodium, which is a vascular, flowerless terrestrial plant that reproduces sexually by homospores and vegetatively through rhizomes, is invaded by class three endophytes that are spread horizontally. Many ailments, including dementia, can be effectively treated with the unique medicinal plants of the Lycopodiaceae family. More than 50 members of the Lycopodiaceae family have been found to contain the significant alkaloid huperzine. A variety of endophytic fungi, including those belonging to the genera Aspergillus, Trichoderma, Alternaria, Paecilomyces, Podospora, Penicillium, Mucor, Cyphellophora, Colletotrichum, Hypoxylon, Acremonium, Blastomyces, Schizophyllum, and Botrytis, were identified with their capacity to produce high concentrations of huperzines.