凉薯（学名：Pachyrhizus erosus），〔在中国某些地区称豆薯、洋地瓜（例如中国贵州地区称「地瓜」、「地萝卜」，它与旋花科别称「地瓜」的红薯无关）、沙葛（粤语）、芒光（潮州话从马来语借词）〕是豆科一年生或多年生藤本植物。其块根肥大，常为心形；外表皮薄但坚韧，易撕下；肉质白色，生吃爽脆甘甜，亦可熟食。

原产中国南部、墨西哥、中北美洲。中国四川、重庆地区和**栽培较多。

豆薯属豆科豆薯属中能形成块根的栽培种，多年生：缠绕性草质藤本植物。豆薯的块根肥大，肉洁白脆嫩多汁，富含糖分和蛋白质，还含丰富的维生素C。可生食，也可熟食。老熟块根中淀粉含量较高，可提制淀粉。种子和茎叶中含鱼藤酮，对人畜有毒，可用以制杀虫药剂。

Pachyrhizus erosus, commonly known as jicama (/ˈhɪkəmə/; Spanish jícama  [ˈxikama] ; from Nahuatl xīcamatl, [ʃiːˈkamatɬ]), Mexican yam bean, or Mexican turnip, is the name of a native Mexican vine, although the name most commonly refers to the plant's edible tuberous root. Jícama is a species in the genus Pachyrhizus in the bean family (Fabaceae). Plants in this genus are commonly referred to as yam bean, although the term "yam bean" can be another name for jícama. The other major species of yam beans are also indigenous within the Americas.