  Let $G=(V, E)$ be an undirected graph. The spanning trees polytope $P(G)$ is
the convex hull of the characteristic vectors of all spanning trees of $G$. In
this paper, we describe all facets of $P(G)$ as a consequence of the facets of
the bases polytope $P(M)$ of a matroid $M$, i.e., the convex hull of the
characteristic vectors of all bases of $M$.
