  We present here high resolution echelle spectra taken during three observing
runs of 14 single late-type stars identified in our previous studies (Montes et
al. 2001b, hereafter Paper I) as possible members of different young stellar
kinematic groups (Local Association (20 - 150 Myr), Ursa Major group (300 Myr),
  Hyades supercluster (600 Myr), and IC 2391 supercluster (35 Myr)). Radial
velocities have been determined by cross correlation with radial velocity
standard stars and used together with precise measurements of proper motions
and parallaxes taken from Hipparcos and Tycho-2 Catalogues, to calculate
Galactic space motions (U, V, W) and to apply Eggen's kinematic criteria. The
chromospheric activity level of these stars have been analysed using the
information provided for several optical spectroscopic features (from the Ca II
H & K to Ca II IRT lines) that are formed at different heights in the
chromosphere. The Li I 6707.8 AA line equivalent width (EW) has been determined
and compared in the EW(Li I) versus spectral type diagram with the EW(Li I) of
stars members of well known young open clusters of different ages, in order to
obtain an age estimation. All these data allow us to analyse in more detail the
membership of these stars in the different young stellar kinematic groups.
Using both kinematic and spectroscopic criteria we have confirmed PW And, V368
Cep, V383 Lac, EP Eri, DX Leo, HD 77407, and EK Dra as members of the Local
Association and V834 Tau, pi^{1} UMa, and GJ 503.2 as members of the Ursa Major
group. A clear rotation-activity dependence has been found in these stars.
