Yunnan wheat (Triticum aestivum ssp. yunnanense), locally known as "Iron Shell Wheat" or "Powdered Head Wheat", is a unique hexaploid (AABBDD, 2n=42) landrace endemic to western Yunnan, China. It thrives in the lower valleys of the Lancang (Mekong) and Nujiang (Salween) Rivers. As a genetically distinct subspecies of bread wheat, it evolved through local adaptation to Yunnan's high-altitude environment. Valued by farmers for centuries, it exhibits enhanced stress tolerance (disease, drought, cold) likely derived from ancestral wild wheats. This exceptional genetic diversity makes it a vital resource for breeding climate-resilient wheat cultivars, offering novel traits to improve global wheat productivity against environmental challenges.