  We describe the structure and different features of Lie algebras in the
Verlinde category, obtained as semisimplification of contragredient Lie
algebras in characteristic $p$ with respect to the adjoint action of a
Chevalley generator. In particular, we construct a root system for these
algebras that arises as a parabolic restriction of the known root system for
the classical Lie algebra. This gives a lattice grading with simple homogeneous
components and a triangular decomposition for the semisimplified Lie algebra.
We also obtain a non-degenerate invariant form that behaves well with the
lattice grading. As an application, we exhibit concrete new examples of Lie
algebras in the Verlinde category.
