Perhaps Googling is not enough. I looked at Catalogue of Life...on this page:
http://www.catalogueoflife.org...
Look near the bottom of the page for 'distribution' it lists..."8 - Southern America, 84 - Brazil, Brazil Southeast (BZL), São Paulo (BZL-SP)";
for 'additional data' it lists..." Lista de Espécies da Flora do Brasil"
Edited to add:
I looked on "Lista de Especies da Flora do Brasil for Pseudeogynoxys chenopodioides and found it listed...native to Brasil but not endemic.
Edited at add:
Lists change all the time; perhaps you are using an older text?
There are other Pseudogynoxys listed in Flora do Brasil...your plant may be P. lobata ( a 'provisionally accepted nam'e), or it may be P. cabrerae which has the synonym P. benthamii