  We present an analysis of the spectral density of the adjacency matrix of
large random trees. We show that there is an infinity of delta peaks at all
real numbers which are eigenvalues of finite trees. By exact enumerations and
Monte-Carlo simulations, we have numerical estimations of the heights of peaks.
In the large tree limit, the sum of their heights is 0.19173 +- 0.00005.
Moreover all associated eigenvectors are strictly localized on a finite number
of nodes. The rest of the spectral density is a function which vanishes at all
positions of peaks, which are a dense subset of real numbers: so this function
is almost everywhere discontinuous.
  Keywords: random tree, spectral density, density of states, adjacency matrix,
localization, delta peak.
