I. Itenberg et E. Shustin, NEWTON POLYGONS AND SINGULAR POINTS OF RE AL POLYNOMIAL VECTOR-FIELDS, Comptes rendus de l'Academie des sciences. Serie 1, Mathematique, 319(9), 1994, pp. 963-968
We classify collections of singular points of generic polynomial vecto
r fields of a given degree in the real plane. The answer is that the u
pper bounds to the number of singularities and to the total index are
the only restrictions. Our solution is based on the Viro method of glu
ing of polynomials, which allows to reduce the singularity theory prob
lem to a combinatorial question on triangulations of Newton polygons.