  When compared to lithium and beryllium, the absence of boron lines in the
optical results in a relatively small data set of boron abundances measured in
Galactic stars to date. In this paper we discuss boron abundances published in
the literature and focus on the evolution of boron in the Galaxy as measured
from pristine boron abundances in cool stars as well as early-type stars in the
Galactic disk. The trend of B with Fe obtained from cool F-G dwarfs in the disk
is found to have a slope of 0.87 +/- 0.08 (in a log-log plot). This slope is
similar to the slope of B with Fe found for the metal poor halo stars and there
seems to be a smooth connection between the halo and disk in the chemical
evolution of boron. The disk trend of boron with oxygen has a steeper slope of
~1.5. This slope suggests an intermediate behavior between primary and
secondary production of boron with respect to oxygen. The slope derived for
oxygen is consistent with the slope obtained for Fe provided that [O/Fe]
increases as [Fe/H] decreases, as observed in the disk.
