Three names for the same vegetable:
甘薯 (formal/written),
红薯 (hóngshǔ, 'red yam', most common everyday term in northern China),
地瓜 (dìguā, 'earth melon', common in southern China and Taiwan). All refer to Ipomoea batatas — the orange/red-fleshed sweet potato. Distinct from
山药 (yam, Dioscorea).
