Resumo: Let X be a planar polynomial vector field with a fixed Newton polytope Γ. Recently, in Dalbelo-Oliveira-Perez (2024), it was proved that the monomials associated to the upper boundary of Γ satisfying some non-degeneracy conditions determine, under topological equivalence, the phase portrait of X in a neighbourhood of the boundary of the Poincaré–Lyapunov disc.
In the present talk we show that there exist vector fields of chief interest which do not satisfy such non-degeneracy conditions but still their phase portraits are determined by the monomials associated to the upper boundary of Γ in the Newton polytope of X and using such a result we can complete classify locally some classes of planar vector fields at infinity in the Poincaré-Lyapunov disc.