甘薯（学名：Dioscorea esculenta）是薯蓣科薯蓣属的植物。

多年生缠绕草质藤本；有卵圆形块茎；每株5～10个；宽心形叶子互生，叶柄基部有刺；初夏开花，穗状花序单生；三棱形蒴果；圆形种子有翅。

甘薯的根分为三种：须根呈纤维状；有根毛，根系向纵深发展，一般在30厘米的土层内，吸收水分和养分；柴根粗约1厘米．可长达40厘米，是须根在生长中因土壤干旱、高温、通气不良等因素，发育不全角成的畸形肉质根；块根是储藏营养的器官，是食用的部分，在5～25厘米的土层中，先伸长，然后长粗。

Dioscorea esculenta, commonly known as the Lesser Yam, is a yam species, but with a smaller corm than most other yams. It is closer in size to a potato or sweet potato. In Vietnam, it is called khoai từ or củ từ. It is used to make chè củ từ, also referred to as chè khoai từ. In Tagalog, it is known as tuge. It is cultivated in Kerala, India. In Malayalam, it is known as "Nana Kizhangu" or Cheruvalli Kizhangu" or Cheru Kizhangu". It is a climber which needs support and goes coiling around the support. The corm is edible.