Triphasia trifolia

Native to tropical Asia and the western Pacific, this is a spiny evergreen shrub or small tree. Fragrant white flowers have three narrow petals, and the fleshy fruits ripen from bright red to dark red. It belongs to Rutaceae, the citrus family. The fruits contain oil glands with a lemon-like scent, and the plant occurs in thickets and secondary forest understory. Its fruits and leaves have traditional medicinal uses, and it has naturalized in Singapore. Photographed in Colombia.