Willughbeia sarawacensis

Willughbeia sarawacensis, commonly known as kubal or kubal madu, is a tropical vine-bearing plant with edible fruit native to Borneo and to the nearby Island of Palawan in the Philippines. The fruit is the shape, size, and color of a grapefruit with a thin melon-like rind and have a concentrated sweet taste comparable to mango, soursop, and pineapple combined. At the government experiment station near Kuching, Sarawak they are grown on elevated platforms and said to start producing in less than two years.