The Atacama Desert, located on the western side of the Andes in northern Chile, harbours a range of endemic species adapted to hyperarid conditions. Vegetationis largely restricted to coastal fog oases and the Andean foothills, which are separated by a largely vegetation-free zone. Diversifications have been shown to be surprisingly recent in some Atacama clades, which is at odds with the extremely long history of aridity documented for this region. Here, we report the results of a molecular dating analysis of the Atacama genus Cristaria (Malvaceae) and its East Andean sister genus Lecanophora based on plastid sequence data.