  This note is concerned with the unipotent characters of the Ree groups of
type G_2. We determine the roots of unity associated by Lusztig and
Digne-Michel to unipotent characters of ^2G_2(3^{2n+1}) and we prove that the
Fourier matrix of ^2G_2(3^{2n+1}) defined by Geck and Malle satisfies a
conjecture of Digne-Michel. Our main tool is the Shintani descent of Ree groups
of type G_2.
