We describe a 2-parameters family of Hopf subalgebras of the non-commutative Connes-Kreimer Hopf algebra of planar rooted trees. They are organized into three isomorphism classes: a first one, restricted to a polynomial ring in one variable; a second one, restricted to the Hopf subalgebra of ladders, isomorphic to the Hopf algebra of quasi-symmetric functions; a last (infinite) one, which gives a non-commutative version of the Faà di Bruno Hopf algebra. By taking the quotient, the last classe gives an infinite set of embeddings of the Faà di Bruno algebra into the Connes-Kreimer Hopf algebra of rooted trees. Moreover, we give an embedding of the free Faà di Bruno Hopf algebra on N variables into a Hopf algebra of decorated rooted trees, together with a non commutative version of this embedding.