It consists of about 169 species of shrubs, lianas or trees, which are native to tropical and subtropical regions of sub-Saharan Africa, the Indian subcontinent, Indochina, southern China, Malesia, and New Guinea.

[1] In 1834, in Prodromus Florae Peninsulae Indiae Orientalis Robert Wight and George Arnott Walker-Arnott describe Millettia as: Calyx cup-shaped, lobed or slightly toothed.

One of the oldest references in traditional Chinese medicine is in Bencao Gangmu Shiyi ("Supplement to Compendium of Materia Medica") where is called jixueteng.

[4] In the 1820s-1830s Charles Millett, a plant collector and an official with the East India Company, collected many samples of Millettia while living in Canton and Macao.

In 1834, Robert Wight and George Arnott Walker-Arnott, both Scottish botanists, published Prodromus Florae Peninsulae Indiae Orientalis where the genus Millettia is first mentioned.

[6] Robert Sweet states that the genus Pongamia comes from the Malabar region in India and is derived from the local word Pongam (most likely from the Malayalam language).

[10] Species are used locally as fuelwood, fish poisons, insecticides, medicine, ornamentals, and nitrogen fixers for soil rehabilitation in agroforestry.