rambutan, (Nephelium lappaceum), tree of the soapberry family (Sapindaceae). It is native to Malaysia, where it is commonly cultivated for its tasty fruit, also called rambutan.Rambutan not only benefits skin but also promotes hair growth and thickness. The vitamin C and antioxidant content inherent in rambutan fruit and juice help to strengthen the roots of hair known as follicles, to stimulate the proliferation of long and robust locks of hair.