Erogonum divaricatum, an annual herb of clay slopes and flats in the Green and Colorado river drainage basin of the western United States, was found at the turn of the century in three locations in southern Argentina. The South American material was described in 1902 as a new species of Erogonum, E. ameghinoi Speg., and this name was the basionym for a new monotypic genus, Sanmartinia M. Buchinger, proposed in 1950. The species has not been rediscovered in Argentina, and the presence of the species in South America was probably the result of a long-distance dispersal event involving shore birds.
Reveal, James L.
"Eriogonum divaricatum Hook (Polygonaceae), an intermountain species in Argentina,"
Great Basin Naturalist: Vol. 41
, Article 6.
Available at: https://scholarsarchive.byu.edu/gbn/vol41/iss1/6