Versal deformation of the analytic saddle-node

We derive simple formsfor saddle-node singular points of analytic foliations in the real or complex plane just by gluing foliated complex manifolds. We give the versal analytic deformation of the simplest model.We also derive a unique analytic form for those saddle-node having a central manifold.By this way, we recover and generalize results earlier proved by J. Ecalle by using mould theoryand partially answer to some questions asked byJ. Martinet and J.-P. Ramis in the 80's