  We check Sakellaridis-Venkatesh conjectures giving a description of the
discrete spectrum of a spherical variety $\mathscr{X}=G/H$ in the
Langlands-Arthur formalism when $G$ is a classical real group and $\mathscr{X}$
is a symmetric space. Then, we compute explicitly the representations in the
relevant Arthur paquets which appear in the discrete spectrum, and we establish
some multiplicity one results.
