Pelargonium fruticosum belongs in the family Geraniaceae, a large cosmopolitan family of approximately 11 genera and 800 species in subtropical and temperate regions of the world. The South African genera in the Geraniaceae family are Monsonia, Sarcocaulon, Pelargonium, Erodium and Geranium. There are approximately 270 species of Pelargonium which occur in south, east and north-east Africa, in Asia, St Helena, Tristan da Cunha, Madagascar, Australia and New Zealand. Most (± 219 species) occur in southern Africa.

Pelargoniums are often wrongly called geraniums. Pelargonium gets its name from the resemblance of the shape of the fruit to the beak of a stork, which is pelargos in Greek. The Latin species epithet fruticosum, meaning shrubby, refers to the habit of the species. The epithet was first applied to this species as early as 1787 when the Spanish botanist, Cavanilles, described it under the name Geranium fruticosum. This description was based on a dry specimen received from the French botanist Thouin. Cavanilles' description was accompanied by a fine illustration of the plant. Botanists however did not recognize it as Geranium fruticosum. In 1835 Ecklon and Zeyher, botanical collectors, transferred the epithet to their genus Myrrhidium which is currently a section of the genus Pelargonium. In 1860, the Irish botanist Harvey concluded that the plant represented a variety of Pelargonium myrrhidium of the section Myrrhidium and called it P. myrrhifolium (L.) L'Hérit. var. fruticosum (Cav.) Harv. The latter was maintained by succeeding authors. The original specimen on which Cavanilles based his description is still housed in the Madrid herbarium. It was discovered that the epithet fruticosum had been applied by later authors to Pelargonium longicaule Jacq. of the section Myrrhidium. The epithet divaricatum Thunb., originating from 1794, had in the meantime also been applied to the present species, but it was predated by the epithet fruticosum (1787); the latter, therefore, has precedence.