The genus Stomatium is placed in the Mesembryanthemaceae family. Members of this family are commonly referred to as Mesembs and are succulents. The genus name was derived from the Greek word stomation which means open mouth, in reference to the toothed leaf pairs which resemble gaping mouths. The novice succulent admirer will at first be easily confused between Stomatium and Faucaria, yet there are a few distinguishing features to tell them apart. Stomatium flowers are scented and give off a sweet sugary smell whereas Faucaria flowers are unscented. The leaf surfaces of Stomatium species are minutely pimpled, unlike those of species of Faucaria, which are either perfectly smooth, rarely warty or ribbed as is the case with Faucaria tuberculosa. Stomatium species also typically have smaller leaves than Faucaria species. The plants are active in the summer and should be kept somewhat dry in the winter. They are hardy, tolerating cold and heat and soil conditions ranging from sandy to heavy. Full sun enriches their purplish tints. They are propagated by seed and cuttings.

Stomatium pyrodorum is another nocturnal blooming species of mesemb from NW South Africa along the Namibian border.