Lower Yangtze Mandarin is one of the most divergent groups of Mandarin dialects, as it neighbors the Wu, Hui, and Gan groups of Chinese varieties. It is also known as Jiang–Huai Mandarin , after the Yangtze (Jiang) and Huai Rivers. Lower Yangtze dialects are distinguished from most other Mandarin varieties by their retention of a final glottal stop in words that ended in a final stop in Middle Chinese.