Mycorrhizae are one of the beneficial soil microorganisms which live in close association with roots of the higher plants and are the integral part of natural ecosystems. Ecosystems are the life- support systems of the man and require these microbes to survive and thrive. Soil inhabiting organisms including fungi, mycorrhizae and bacteria are very well known for playing an important role in the soil by simplifying the complex organic matter in ecosystem. This monograph mainly depicts the diversity of VAM fungi, colonized in the rhizospheres of various ethnomedicinal plants of Himachal Pradesh. This monograph contains total five chapters, references and annexure along with 26 plates, 16 figures and 38 tables. We hope that this monograph will serve as a focal point for further studies on the diversity and interactions between plants and microbes. The taxonomy part with images of endomycorrhizae and ethnomedicinal plants will definitely help the students, researchers and teachers in the field of mycorrhizal research, identification, development of inoculation technology for plant health and also it will stimulate further progress in the field.