Pelargonium desertorum is a summer deciduous, much branched, aromatic, dwarf shrublet reaching 30 cm in height and spreading. The species was first collected in 1975 and described later.
The dark purple upper petal markings on the white corollas will not be missed. So are the olive to purplish brown inside surfaces of the acutely pointed sepals, the margins paler.
The species distribution is small, restricted to far northwesterly mountains of the Northern Cape near the Gariep River, the north of the Richtersveld and also the southwest of Namibia.
The habitat is succulent Karoo veld on mountain tops and slopes. The plants favour south-facing slopes of granite-derived soils where the little rain falls in winter. The habitat population is deemed of least concern early in the twenty first century (Williamson, 2010; iNaturalist; www.namibrand.com; http://redlist.sanbi.org).