  [Abridged] Contex. Young open clusters provide important clues to the
interface between the main sequence and pre-main-sequence phases of stellar
evolution. The young and nearby open cluster IC 2391 is well-suited to studies
of these two evolutionary phases. Aims. We establish a bona fide set of cluster
members and then analyze this set in terms of binary frequency, projected
rotational velocities, [Fe/H], and lithium abundance. In the wake of the
Hipparcos distance controversy for the Pleiades, we compare the main-sequence
fitting distance modulus to the Hipparcos mean parallax for IC 2391. Results.
The proper-motion survey covers a 6 times larger sky area than the prior
targeted searches for cluster members in IC 2391. A total of 66 stars are
considered bona fide cluster members down to a mass equivalent to 0.5M_sun. A
quarter of them have been newly identified with many in the F2-K5 spectral
range, which is crucial for a main-sequence fit. We find a mean [Fe/H] value of
+0.06+/-0.06, when a solar abundance of log epsilon (Fe)=7.45 is adopted. The
main sequence fitting yields a distance modulus that is 0.19 mag larger than
that derived from Hipparcos parallaxes; thus this offset nearly has the size of
a similar offset found for the Pleiades. The Li abundance pattern is similar to
the earlier findings and is typical for a 40 Myr old open cluster.
