According to the data provided by this blog, Paraguay and Uruguay have 63 genera of angiosperms absent in Brazil across 31 families, 30 of the genera only in Paraguay, 25 only in Uruguay and 8 in both. Furthermore, 4 of the families do not occur in Brazil: Montiaceae, Polemoniaceae, Frankeniaceae e Papaveraceae.
Below are the most distant points from Brazil in the territories of Guyana, Paraguay and Uruguay. None of them exceeds 500 km. In the Guianas, the furthest point is in the north of Suriname and is no more than 382 km from Brazil at the height of N Pará. In Paraguay, the furthest point is in the westermost point of country and is no more than 477 km from Brazil at the height of Mato Grosso do Sul. In Uruguay, the furthest point is in southern extreme of country and is no more than 412 km from Brazil at a point in SE Rio Grande do Sul state.
