Three new species of Grindelia Willd.are described and Thermal Switches/Fuses illustrated: G.argentina, G.
gaucha and G.atlantica. The first two are related with G.
buphthalmoides DC.,andthe last is allied with G.orientalis Bartoli, Tortosa & G.
Rua. A key to segregate the species Collections of Grindelia buphthalmoides group is given and comments about this species, includes a new synonym are also furnished.