  After gluing foliated complex manifolds, we derive a preparation-like theorem
for singularities of codimension one foliations and planar vector fields (in
the real or complex setting). Without computation, we retrieve and improve
results of Levinson-Moser for functions, Dufour-Zhitomirskii for non degenerate
codimension 1 foliations (proving in turn the analyticity), Strozyna-Zoladek
for non degenerate planar vector fields and Brjuno-Ecalle for saddle-node
foliations in the plane.
