The genus Fagopyrum is in the flowering plant family Polygonaceae, and includes some important food plants, such as F. esculentum (common buckwheat) and F. tataricum (tartary buckwheat). Except for these two cultivated species, the other buckwheat plants are all wild species. They are mainly distributed in southern China in general, and in Yunnan Province in particular. However, our understanding of their richness and geographic distributions in Yunnan remains very limited. The aim of the present study is to establish a list of buckwheat species found in Yunnan, examine their geographic distributions and patterns, and analyze their conservation and utilization status. The results showed a high richness of buckwheat plants in Yunnan, which accounts for nearly 70% of the global buckwheat richness. Species such as F. capillatum and F. gracilipedoides are endemic to Yunnan, and they exist nowhere else in the world. Also, the northwestern Yunnan and central Yunnan regions represent two important distribution centers of buckwheat species in Yunnan, and the highest buckwheat richness was found at the altitude range of 1500–3000 m. Many buckwheat species are rich in amino acids, fiber, vitamins, minerals and bioactive substances. They are also adapted to the high-altitude regions in Yunnan with harsh climatic and soil conditions. As climate change has direct impacts on agricultural biodiversity and food security, the conservation of diversity in buckwheat species, which have both high dietary beneficial components and great ecological adaptability, merits more attention. We believe that it is important to find a balance between the protection and utilization of buckwheat resources in order to achieve the sustainable utilization of this precious natural resource.