Pelargonium lanceolatum 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. The genus Pelargonium has approximately 270 species which occur in S, E and NE Africa, Asia, St Helena, Tristan da Cunha, Madagascar, Australia and New Zealand, most of which (± 219 species) occur in southern Africa, with a large concentration of more than 135 species in the southern portion of South Africa between Nieuwoudtville in the west and Port Elizabeth in the east. Pelargoniums are often incorrectly called geraniums. The genus Pelargonium gets its name from the resemblance of the shape of the fruit to the beak of a stork, pelargos in Greek, while the Latin specific epithet, lanceolatum, refers to the lance-shaped leaf, which widens above the base and narrows to the apex.

The son of Carl Linnaeus first named this species as Geranium glaucum L.f. in 1781. Although this is the earliest name for this species, it could unfortunately not be used because Nicolaas Burman (Burm.f.) had already used the same name to describe a different species in 1759. Burman's Geranium glaucum Burm.f. is a synonym for Pelargonium ovale (Burm.f.) L'Hérit and G. glaucum L.f. is a later homonym of G. glaucum Burm.f. Article 64 in the International Code of Plant Nomenclature states that a later homonym or a combination of both is prohibited (Schonken). Therefore Geranium glaucum L.f. and Pelargonium glaucum (L.f.) L'Hérit. are both illegitimate names. The next earliest correct name is Geranium lanceolatum of Cavanilles (1787). Thus the legitimate name is Pelargonium lanceolatum (Cav.) Kern.

In 1775 the species was introduced into England by Kennedy and Lee. A botanical magazine of 1787 states that Lee, an owner of vineyard nurseries in Hammersmith, near London, was looking at herbarium specimens of the plant at the Banks herbarium when he discovered viable seed. He then germinated these seeds and raised plants from them. This meant that although he did not bring the actual plant material back from Cape, he was responsible for introducing the species into cultivation.