  We present optical spectra of the nuclei of seven luminous (P(178MHz) >
10**25 W Hz**(-1) Sr**(-1)) nearby (z<0.08) radiogalaxies, which mostly
correspond to the FR II class. In two cases, Hydra A and 3C 285, the Balmer and
4000A break indices constrain the spectral types and luminosity classes of the
stars involved, revealing that the blue spectra are dominated by blue
supergiant and/or giant stars. The ages derived for the last burst of star
formation in Hydra A are between 7 and 40 Myr, and in 3C 285 about 10 Myr. The
rest of the narrow-line radiogalaxies (four) have 4000A break and metallic
indices consistent with those of elliptical galaxies. The only broad-line
radiogalaxy in our sample, 3C 382, has a strong featureless blue continuum and
broad emission lines that dilute the underlying blue stellar spectra. We are
able to detect the Ca II triplet in absorption in the seven objects, with good
quality data for only four of them. The strengths of the absorptions are
similar to those found in normal elliptical galaxies, but these values are both
consistent with single stellar populations of ages as derived from the Balmer
absorption and break strengths, and, also, with mixed young+old populations.
