The genus Aptenia belongs to the Mesembryanthemaceae or vygie family. The family name is derived from the Greek word, mesembria, meaning midday, and anthemom, meaning flower, referring to the flowers that open in the afternoon (noon).

The genus name, Aptenia N.E.Brown, is derived from the Greek word, apten, meaning wingless, and refers to the wingless seed. The species name, cordifolia is derived from the in Latin words, cordi, meaning heart, and folium, meaning leaf.

This genus is endemic to South Africa and consists of four species, Aptenia geniculiflora, A. haeckeliana and A. lancifolia. They all occur in the summer rainfall regions of South Africa.

Aptenia geniculiflorais is an erect deciduous perennial with 4-angled branches. It bears white to pale yellow flowers and occurs on dry flats in scrambling bush found in Namibia to Eastern Cape.

Aptenia haeckeliana is a succulent perennial, grows flat on to the ground, and the stems are 4-angled. The leaves are flat; flowers are pale yellow. It occurs in karroid flats from Port Elizabeth to Alexandria.

Aptenia lancifolia (purple aptenia) is a perennial succulent, 300 mm high. It bears magenta flowers with narrow or lance-shaped leaves and occurs in the Northern Cape.