Let $X$ be a Banach space and let
$F:X\to X$ be a $C^1$ mapping
with fixed point $0$: $F(0)=0$. We give conditions which imply
that
if the $\omega$-limit set of a trajectory contains $0$ then either
the
$\omega$-limit set equals $\{0\}$ or else it contains
a point of the
unstable manifold of $0$ different from
$0$. The hypotheses on
$F$ involve the spectrum of $F'(0)$ (implying
the existence of
stable, unstable, and center manifolds of $0$) and the
dynamics of
$F$ on the center manifold of $0$.
In a number of particular
cases this result allows one to prove
convergence of trajectories
to a single equilibrium.