水黄皮（学名：Millettia oraria）是蝶形花科崖豆藤属的植物，为乔木植物，分布于印度、中国、日本、马来群岛、澳大利亚和太平洋三大岛群

水黄皮是生长高度为15-25公尺的半落叶乔木，寿命可达100年。种植5年后开始开花，花朵为白、紫或粉红色，成熟的豆荚为褐色。根系发达，为耐旱的阳性植物，其共生的根瘤菌可固定空气中的氮气。

Millettia pinnata is a species of tree in the pea family, Fabaceae, native in tropical and temperate Asia including parts of Indian subcontinent, China, Japan, Malesia, Australia and Pacific islands. It is often known by the synonym Pongamia pinnata as it was moved to the genus Millettia only recently. Common names include Indian beech, Pongam oiltree, karanj (Hindi), honge (ಹೊಂಗೆ in Kannada), pungai (புங்கை in Tamil), kānuga (కానుగ in Telugu), karach (করচ গাছ in Bengali), naktamāla (नक्तमाल in Sanskrit).