The Fabaceae family is the third largest flowering plant family. Worldwide, it contains approximately 650 genera and 18 000 species. In South Africa, there are 155 recognised genera and 1 516 species. Liparia is endemic to South Africa's Cape Floristic Region, and L. hirsuta is one of 20 species within the genus.

Liparia is derived from the Greek word liparos, meaning oily and shiny, either in reference to the waxy, fatty surface of the leaves, or its smooth, shiny flowers. The species name hirsuta originates from the Latin word hirsutus, meaning hirsute or hairy, possibly in reference to the hairy calyx.

The genus Liparia was initially described and published by Linnaeus.  He placed six species within the genus but only described two (in 1771), L. sphaerica  and L graminifolia, with L. sphaerica  being the type species of the genus.  Judging from its detailed description, it may have been described from several flower and fruit samples, and possibly cultivated in a conservatory.  Thunberg (1794-1800) later described several new Liparia species.  In 1825, however, de Candolle studied the characeristics and definitions of the genus, and as a result only accepted the description of one species, L. sphaerica.  The excluded species were grouped into separate genera: Priestleya, Rafnia, Borbonia (which included L. hirsuta), and one incorrectly identified Liparia turned out to be a Psoralea.

Following a study on the morphological and alkaloid characteristics of Liparia and Priestleya by Schutte and Van Wyk (1994), and a subsequent revision of Liparia by Schutte (1997), it was suggested that the two genera be combined.  They share similar leaf shape, size and venation patterns, simple racemose inflorescences (wth a variable number of flowers), lengths of peduncle and inflorescence axes.  When P. hirsuta has closer to 12 flowers, the inflorescence axis becomes shorter and bracts become larger and petaloid, thus creating a nodding motion.  In this instance it resembles the head-like nodding inflorescence of Liparia parva and L. splendens.  Fewer flowers and a short axis length will cause a decussate, four-flowered inflorescence similar to P. capitata, or paired flowers similar to P. boucheri.  Furthermore, Liparia and Priestleya share a similar alkaloid combination, and any variation in floral structure and inflorescence may have resulted from adaptations in pollination mechanisms.  As a result, it was proposed that Priestleya be placed in synonymy under Liparia.