[Wikipedia] Monospecific Genus: Thingia is a monospecific genus of flowering plant in the family Montiaceae comprised only by the species Thingia ambigua, known as desert pussypaws. It is native to northwestern Mexico, California, and Arizona, and is found commonly on sandy or silty soil. The sole species of the genus has been housed under several genera before it was split into Thingia: Claytonia in 1882, Calandrinia in 1893, and Cistanthe in 1990. DNA evidence demonstrated that the relationship of Thingia ambigua, then Cistanthe ambigua, to the next closest relative in Cistanthe, C. tweedyi, was actually disjointed. It was found that the two species were most closely related to completely separate South American taxa. (link added by Mary Ann Machi)